"It is important to note that the 2C you are talking about is surface air temperature. It is less than 1 percent of our climate overall. The oceans are a vast reservoir of thermal sink, as is the stratosphere."
Right, but that's a sustained 2C, you can't have one thing at 2C and an adjacent thing much lower. Heat transfer occurs from hot to cold and the rate of transfer is proportional to the difference in temperature. To maintain a 2C surface temperature increase that means everything else must have increased too so pretending only 1% of our climate is going to increase in temperature is utter nonsense - the entirety of the oceans and stratosphere must also drastically increase in temperature for that 2C increase in surface temperature to be sustained, otherwise you wouldn't get a sustained 2C increase because the temperature would just be pulled into the oceans and stratosphere.
Just because the surface temperature is commonly cited doesn't mean that's the only thing changing, everything else has to increase too, it's just more convenient to quote the only immediately obvious temperature to your average human - that which they're sat in day in and day out rather than to quote all the possible ecosystems that will increase by their relative but varying amount.
"Local effects will be more extreme - milder arctic winters and longer growing seasons should improve crops in Russia, Canada and northern Europe."
Right, central and southern North America, Australia, and much of Africa and the Middle East will become too prone to drought for any reliable crop growth. Why just focus on the areas where crop yield potential will improve and ignore the vast swathes of the Earth where agriculture will become impossible unless you have some kind of insanely biased agenda here?
"Africa will see more precipitation turning the Sahara into grassland again."
Great, that's Europe and South America fucked then given that dust from the Sahara blown to those continents is essential for the fertilisation that allows the high levels of green growth.
What, you thought you could change a major ecosystem in the globe like the Sahara and there wouldn't be impacts elsewhere? that's not the way the world works.
"This may stress reefs, but really - they are millions of years old and have seen this before."
Not on a timescale that leaves no time for adaptation via evolution.
At first you seemed to have an extremely over simplistic understanding of the natural world, and that that was leading you to reach a gross underestimation on the negative impacts global warming would have, but your cherry picking of the benefits and certain statistics implies it's not necessarily that you don't or couldn't understand the respective elements of the natural world, but that you're being intentionally dishonest to push a short sighted and selfish view.