The fourth question is complicated -- there obviously are both positive and negative consequences. As far as I remember it is usually held that the positive consequences (e.g. better harvests, etc.) overwhelm the negative until the about +2 degrees C rise in the temperature, but it's all very uncertain.

Robin Hanson did an article which estimated this, but as far as I'm aware it's not "usually held" to be true. I've often found Hanson to be particularly incautious in his reasoning, and this is no exception. There are a lot of factors that this fails to account for (such as increasing ocean acidification and its various knockoff effects,) and I wouldn't put much stock in the specifics.

There are certainly prospective benefits to climate change, but one thing I've often encountered as a rather substantial framing problem in the discussion is that people often ask "how warm do we want the planet to be?" when the important question is "what rate of climate adjustment most benefits us?" Since at our current rate we're adjusting global climate on a timescale of decades which ecosystems more commonly adjust to over timescales of tens to hundreds of millennia, the issue is not so much the temperate change, but the rate.

Overall, I feel the climate science has been hijacked by fearmongers who use the hysteria to push their agenda and/or just to get money.

I hear this viewpoint expressed frequently, but I find the "money" motive rather confusing. Getting university tenure is very difficult, and not that lucrative, whereas at least as of the time of my graduation, there were both more lucrative and more numerous openings available working in industry in sectors with a vested interest in continuing "business as usual" operations. Most academic climate scientists believe that anthropogenic climate change is taking place, and that it's liable to cause significant problems, yes, but that doesn't mean that if you want to enter the field and make money, you want to match the mainstream position in order to improve your chances of getting a tenured position, because most of the slots for professional academic scientists are already taken, and it's not a great way to earn money to begin with.

In any case, academic scientists generally work less for money than for prestige. As a result, there's always reputational incentive not to adopt something too far from the mainstream position, to avoid being seen as a crackpot, but there's also some countervailing pressure to differentiate yourself to some extent, because the ones who depart from the herd and are proven to be correct reap the most status.

In my experience dealing with climate scientists, I've generally found that rather than being eager to receive new studies suggesting major negative consequences of climate change, their attitude tends much more towards "oh god, not another." Skepticism that anthropogenic climate change is actually happening is practically buried among climatologists at this point, but research suggesting that its effects will not be seriously problematic tends to be quite welcome.