a one, and-a two, and-a three...
1. New springs are inevitable. Get them now.
2. Putting in new springs now will have no effect on being able to do a revalve later. Might duplicate some labor expense.
3. The stock shock spring (5.0kg/mm) should be fine.
4. You don't need to be mechanically 'gifted' to change your springs. Consider that the oil in the forks needs to be changed a couple times a year, which pretty much involves the same work as changing the springs. You going to pay someone to do that, too?
If not 'gifted' means you don't consider torque values when assembling something...or if you take apart a 1,2,3 piece and don't know if it goes back together 3,1,2 or 2,3,1..then pay the man.
Who's doing your carb tuning?? That takes as much 'gift' ...and that's ALways something that needs tweaking.
Line up a couple of brew-skis, do some research on springs and stuff on this site (like check out MAD's site) and give it a go!
Heck..even if you take it to someone to be done, you can STILL enjoy the brews!!
Oh..re: top-end power. A rev pipe doesn't so much 'add to' the top end as it shifts the power band 'up' within the existing range. The 220 is short-breathed in large part due to its 33mm carb. Boring it to 36mm costs less than a pipe...although you need that, TOO! ;)