This is a strong downside to Texas. It is very hard to get around without a car. You might be able to live in downtown Austin without a car, but that's a pretty expensive part of town. And once you want to go anywhere else, you'll want to drive.
Downtown Austin, btw, is not good thinking territory. It's super crowded. I mean crowded. I mean, many streets are simply not accessible for driving on because they are so packed with drunk college kids. It's fun and frenetic, but it's an attraction not a lifestyle.
Houston? San Antonio? Dallas? All cities with their own vibe, but they are not walking cities at all. Texans have vast tracts land and boy o boy do they USE it.
I would avoid Waco, mostly because I-35 is so central to the North/South traffic flow there and is so terribly always in a state of disrepair and repair and demolition and re...molition... Waco is also a college town, but it's a very conservative college town. You'll get the college town downsides, but not many of the upsides. The only thing in my mind that is a merit to Waco is that it isn't far from West and in West you've got Kolaches. (I went to Baylor, briefly, in my younger days and soon fled.)
I live in Austin. I've lived a long time in North Austin, South Austin, and now I live in Travis Heights / SoCo. This was broken up by a 12 year stint in Bellevue, WA.
Some thoughts:
The I-35 corridor through downtown is not a great drive. If you live North of downtown, you'll tend to want to stay up there. If you live South, you'll tend to want to stay down there. In my mind, South of downtown (anywhere south/east/west as long as you don't have to commute through downtown) wins in the exchange. North Austin is a flat, uninspired land that more resembles Dallas in its uniformity. If you live North, you'll want to drive South for your entertainments. This means driving through the I-35 (or Mopac) chokepoints which will add time and lower happiness.
Mosquitoes can be handled with some oscillating fans (disrupts flight and oderants/co2 they use to track you). They'll still find you, but it can be managed. I haven't noticed much of a problem with them while out walking. Stationary outdoor talking/reading with no fans is more the problem.
The weather is very hot in August, but in trade you get an early end to winter and wonderful spring weather. Thunderstorms are rare, but powerful and inspiring. Winter is generally mild.
The fried chicken scene here is ace.
Note that Texas BBQ is a beef and oak dominated ordeal, so you'll find a lot of brisket. We still serve up ribs, but unlike our cousins in Kansas City, the brisket is the artform and the rib takes a lesser role.
You won't find very much good Thai food or Indian food. Yes, there is some, but you aren't going to find it at quality for delivery. There is a little Sushi, but not as much as you'd expect. There is a lot of excellent Pho and Ramen. There is very little good Chinese.
There are a number of restaurants on the river. These aren't always the best in terms of food...but they are on the river and you can hang out and drink iced tea and watch the sun go below the tree line. That's good thinking.
On the front of thinking: something you might consider is the ability to drive to a camping location in Austin. There are a number of camping parks you could take a vehicle, tents, and people, and get away from the city and noise and just hang out and talk (or fish, or hunt). Driving to any of a number of nearby small towns with their own attractions and camping locations gives you lots of options.
Many, many people have nice outdoor areas at their homes for hanging out.
There is a nice public pool system. There are a few public springs. There are several outdoor and indoor waterparks not far. There are places for lazy river floats.
Texas wine country - such as it is - is also an hour away in Fredericksburg.
To me, Austin is surrounded by places to just go and think or read whether solo or with compatriots.
Finally, a warning. The food here is seriously good and quite rich and very cheap. You really do have to be careful about the quantity you eat. Everyone will want to feed you.
Gardening can be a challenge here. If you enjoy gardening it is doable, but water conservation rules, frequent droughts, and relentless sun exposure mean you'll need to be strategic and ... try things.
(I wrote a post laying out some notes about Austin, but wasn't logged in. When I logged in the post was lost. So, this is a note for the site developers that this is a pretty bad failure case.)
I'll have to hit you up about LW meet-ups in the area. I didn't like the ones I attended in Seattle and as a result I became very adjacent to the community. I also have kids, which consume a lot of time. It would be nice to have some grown up friends.