Cant be too much hassle to replace a few caps. I've never done it on an Amiga but i have successfully replaced the caps on a sega gamegear and that is small and i am honestly no good at soldering. If you are considering a new motherboard you have nothing to lose by attempting to replace the caps first. Just take your time and do it slowly and you should be fine.
But buy some proto boards and components first to practice on. I spilled solder and it went under one of the chips. My A1200 was never the reliable after that.
