As a former teacher, I firmly believe that if we want to reform schools, we must reform the teaching profession and school management structures. At least, we should address the things that are most insane:

• A school district is a big operation, with many having thousands of employees, and budgets running into the hundreds of millions of dollars. And it is usually run by literal amateurs. As in, the school board is a group of unpaid volunteers.
• As tough as it is to be a teacher, consider what it's like to be a principal: You get the most odious parts of being a teacher (dealing with discipline, contentious meetings with parents), with a longer workday, shorter (if any) summer vacation, much greater responsibility, much greater public exposure (and corresponding chance of getting fired for some perceived failure), but not really that much more pay. It's hardly surprising that it's hard to find good people to take that job. So, as a teacher, you can't count on competent support from management. But, you really need it.
• The teaching profession takes a lot of skills. Yet, the job description for a first year teacher, and the job description for a 30th year teacher are identical. Imagine hiring an engineer fresh out of college and asking them to do what a senior architect does.
• But, from a practical standpoint, the job of the inexperienced teacher is often much more challenging. The experienced teacher gets to pick the honors classes, the electives, etc., to teach. The inexperienced teacher gets stuck with the remedial classes. It's not uncommon for a new teacher to get hired to teach class sections that were added at the last minute -- and those sections will be full of students who got put into those sections at the last minute, because they didn't have their act together, didn't pass, didn't register, etc.
• As you discovered, an inexperienced teacher will find it a lot of work to deal with even one or two classes. Where I work now, if someone was asked to conduct a training session, they might spend a couple days prepping. We ask teachers to do 5, 6 even 7 of those per day, only not with well-mannered professional adults, but kids whose brains are not fully developed. And then grade homework, call parents, be hall monitors, function as social workers, etc.

I could go on.

There are many problems one could bring with various approaches to teaching. There are many challenges that teachers would face even in the best of systems. But fundamentally, there are some serious structural issues with the design of the system.

Ironic that "Maybe" seems to have one of the narrower ranges of probabilities...

The cell borders example is misleading. The readability issue is not the cell borders themselves, the issue is that the borders are heavier weight than the text, and there's no difference between the borders separating the row and column headers, and the borders separating the data rows and columns.

If your only choices for gridlines are "off" and "obnoxious", "off" seems like a good choice. And for small tables, no borders works well. But for larger tables, finer lines (maybe in a lighter color or shade) can really improve the readability.

In multiplayer games, one balancing factor is that other players can gang up on the person who is ahead. Depending on the game dynamic, this can even things out a lot. In some games, this even creates the dynamic where you don't want to look too strong, so that others don't focus their attention on you.

Playing games against my kids when they were young, rather than just slack off and let them win, it was more fun for me to figure out the best way to handicap myself: What algorithm for sub-optimal play would keep the game close? Solving that puzzle effectively became my victory condition, rather than the game's victory condition, and I was effectively competing against myself, a more balanced opponent.

The question of what IS happening versus what SHOULD happen with population growth are certainly two different things. My point is that arguments for growth ultimately need to address the questions of how big should we grow, and what happens when we reach that point. If our economy depends on continued growth, that's going to stop working at some point.

While the physical limits of the universe are a long ways off, there are other limits that we could hit much sooner. Underlying your pro-growth arguments, there is an assumption that collective intelligence can continue to grow without limits, leading to technology that can grow without limits. I would question those assumptions.

And of course, your post is ignoring the costs of growth. Ideas are non-rival goods, but space on this planet, and physical resources, are rival goods. If intelligence (and the resulting technology) reaches a point of diminishing returns, but the costs of growth hit an upward inflection, you quickly hit a limit. For example, larger, more complex systems risk becoming less stable, while coordination problems can grow factorially.

Reasonable people can disagree on whether the current population is too big, too small, or about right, but "ever larger" is not going to work as an answer. At some point, we need to either figure out how to have a stable population, or deal with the less pleasant alternatives.

The fundamental problem with these anti-Malthusian arguments is they ignore the fundamental reality that exponential growth is unsustainable. There are physical limits to the universe, whether you believe the earth can support 10 billion or 100 trillion, or if we can expand through the universe and achieve a billion billion times more than that, it won't take that long, with exponential growth, to get there. At a certain point, the entire mass of the universe has been converted to human flesh. Some point before that, we either stabilize, or collapse.

Maybe we get past the obvious physical limits by ditching human bodies and uploading to the matrix. But, that only gives us a few more orders of magnitude.

And note that sub-exponential growth is mathematically equivalent to saying that the growth rate approaches zero.

So, it becomes a question of what the ideal max population level should be. The answer will clearly change based on available technology, but is not unlimited.

Where I live, I don't see many people going 15 over. I see most people going within -3 to +9 of the speed limit. They're following the law -- maybe not strictly as written, but as socially understood. There are a few people breaking the law -- and they get ticketed, etc. There are places where the speed limit is unreasonably low, and gets ignored (e.g. speed limit drops from 75 to 55 for construction zone, but no construction activity is visible), but in general, people around here follow the speed limit -- as socially understood.

The social definition is that +9 is OK, and it is logically based. Speed limits are only given to the nearest 5 MPH, so arguably (not legally arguably, but in people's heads) going 4 MPH over is not really speeding. Then, you need some kind of reasonable cushion. It defies common sense (but not the law) that a certain speed is perfectly legal in a variety of reasonable conditions, but 1 MPH faster than that is a crime. So, you have to have reasonable padding, say one 5 MPH increment. Thus, if you're going within 9 MPH of the speed limit, you're not speeding, just bending the speed limit, pushing into that safety margin.

Bumping a speed limit from the current value of 55 (+ social tolerance) to 65 (no tolerance) would not work. It would quickly become 65 (+ social tolerance), because you have not addressed the arbitrary nature of the speed limit. With strict enforcement, you could reduce the social tolerance value (I believe it was smaller before the 1970s national speed limit of 55 fostered widespread disrespect for speed limits), but it would difficult to eliminate it.

Yes, when it comes to ordinary driving situations, there's only so good you can get, if you can get from A to B without trouble, without annoying and/or scaring your passengers or other people on the road, it's hard to do noticeably better. It's hard to get too much above the median; the 80th percentile driver won't seem that different from the 50th percentile driver. But, you can be really bad and drag the average down. Thus, the average is below the median, ergo most people (most drivers, anyway) are above average drivers. (Even assuming we are using some identical, objective scale, which, as jefftk points out, is not going to be the case.)

Just be careful your secure grip doesn't inadvertently cause the child an arm injury. "Nursemaid's elbow" and certain types of radial fractures can result from a hard yank on a child's arm.