i actualy hit one of those wisp things while on a small island in the middle of the ocean with nothing else in sight.... running wasn't an option :(.
for ic2 startup i generaly:
1. collect wood
2. dig temporary underground base
3. start burning wood into charcoal
4. make staircase from base to lvl 12
5. dig around for tin, copper and redstone.
6. go back up and search for a rubber tree.
7. create generator, extractor, macerator and batbox (in that order)
8. start building solars
after that i just do what i want realy. no real order of doing things.