I bought an oil-free twin Hitachi silent (50l, I think) to replace my el-cheapo supermarket/Wolf branded 24L(?) one... it is so nice when it kicks in an all you get is a bit of humming in the background.
I use it more because it is quiet.
Main uses are tyres, blow gun and die grinder which is used a lot. I have sprayed with it, but smaller items (suspension rebuild on Audi CQ20V), but I am sure I could spray with it -I did with the old one at least to satin finish MOD paint and got good results, so doubt I would struggle with this. HVLP guns help in this regard, and with the compressor being oil free means that is one less thing to worry about if trying to do something more with 'pretty' paint.
For a welder, MIG is great, point and squirt and with practice you will get better and better.
If I were starting out, but had some cash to spend I would absolutely look at one of the all-in-ones (MIG, TIG, Arc/MMA), as for a DIYer you'll often very quickly run out of space, and not having two welding carts kicking about is much better. You can get a reasonable one from around £1500 onwards, which given a DIY MIG is the thick end of £600 these days is not that bad in reality.