1 - It's not just about less solubility of co2 in water at higher temperature. Higher temperature also speeds up release of co2 by decaying material, the breakdown of volcanic material into soil via increased woody biomass growth, and an unknown number of other processes. There are always two sides to the equation - emission and absorption.
2 - The positive feedback you mentioned usually refers to a theoretical claim that increased co2 will cause an increase in water vapour (a far more powerful and prevalent greenhouse gas). But this has not been observed in the real atmosphere. That indicates that the hydrological cycle has room for self regulation as temperature increases. A study of paleo data confirms this. If it wasn't true, then we would have had runaway positive water vapour feedback when co2 level were 20 times higher than now a five hundred million years ago and the ocean would have evaporated. It didn't, instead the was a huge expansion of life in the ocean called the Permian explosion.
The increase of temperature due to a doubling of co2 is theoretically around 1 degree Kelvin or ~2 degrees fahrenheit. So far, since the pre-industrial period, airborne co2 has risen around 40%. Because the response is logarithmic, we should already have seen most of the effect of the doubling - about 0.8K. However, the surface temperature has risen by around twice that amount since 1700. Therefore, at least half of the warming is the natural rebound from the little ice age.
All systems with negative feedbacks in them oscillate around a mean. A good example is the mechancal governor on an older engine. As the engine speeds up, the governor reacts to reduce the fuel or air supply. That makes the engine slow down, making the governor react by opening up the fuel or air supply. That makes the engine speed up again. Because there is always a lag in the system, you get the familiar 'hunting' effect.
Similarly, the Earth has a warming and cooling cycle of around 1000 years. This has been confirmed through paleo data and historical archaeological data. I think my research group has discovered the cause, but I'll leave that for another day. For now, it's enough to know that at least half the warming since 1700 has a natural cause. The cooling from the Medieval Warm Period to the depths of the Little Ice Age and the subsequent upturn to the Modern Warm Period represent a swing of around 1.5-1.8K.
Clearly, that natural warming has also helped to increase co2 in the air, so not all of the airborne increase is due to human activity and it could well be only around half. The western world crippling its economy by reducing co2 emission over a short timescale before we have developed alternative means of energy generation would therefore have very little effect on the planet's surface temperature. Especially considering the fact that much of our emissions are from agriculture not power generation anyway. There's not much we can do about that unless there is going to be a deliberate plan to compulsarily reduce population. Something I'm strongly against not on any religious principle, but on the principle of liberty, which I hold dear. I have no wish or need to submit myself to authoritarian control, and I think most people agree with me on that.
I agree with you that it's sensible to get on with the job of finding alternatives, but I strongly disagree that we need to be in a huge hurry doing it. In fact the greater the hurry, the more counter-productive the outcome, because we'd be less likely to make the critical technological breakthroughs living in a crippled economy.