1) Q45 throttle body - I have buddies who have done this when going KA-T. I assume it will require a retune as your motor will be consuming alot more air, causing it to lean out. So thats not so cheap.
2)s14 cams are 232/232 duration. Replace the intake cam with an s13 exhaust cam, making it 248/232 and giving it more punch throughout the powerband. Read up here:
zerothread/152578
3)I dunno
4)Why was this hard to search for? It's in the Tech Articles section.
http://www.nicoclub.com/articles.php?id=158170Some ppl like 248/232 better than 248/248 and vice versa. And some ppl prefer to regrind the original s13 setup instead (240/248). But I don't have any info on that last one...