This is why no-one drives my car but me [unless they work for a shop where I'm having work done.] You can only diagnose so much over the internet, but it sounds like your "friend" has done some serious damage.
There is the possibility that he tore the lower shift bushing while beating the hell out of your car, but I doubt it. In general, speed shifting is horrendously abusive on syncros and shifter forks and there's no good reason to do it.
Changing bushings and oil won't really fix problems that are internal to the transmission. If you can't get the car into gear, or if it pops out of gear at speed, your transmission is probably in need of an overhaul.
And based on past experience, I would a buy a rebuilt transmission instead of taking chances on a junkyard tranny that no-one has inspected.
__________________
:: :ToDspin: - supermod
- but who gives a shit?
:: HAN Integra FAQ: If, by some miracle, yours hasn't been stolen... check it out!