honestly, i dont think its worth all the work. an l67 swap would be way more reliable and you can make good power on stock internals.
1) not sure how much boost youll be able to handle. you should be able to achieve a decent amount on stock internals.
2) fuel efficiency will probably go down a little because youll most likely be on it more.
3) YES buy a boost controller.
4) you need to tune yourself. i think DHP tuner will tune OBD 1.5 but if not youll have to swap to OBD 2 to get full benefits.
on top of this. you should check all of your suspension components' conditions. you dont want to be going 100 mph and have a ball joint fail.
your transmission is going to give out too.
