question about shifting and exhaust

hi i have a 98 integra ls with about 60,000 miles for my 1st question i got a short shifter for ebay (cheap $25.00 one) and at 1st didnt seem to have any problems but now sometimes when i shift it grins gears most of the time just 2nd sometimes 3rd i took it to a shop and he said that there wasnt anything wrong with it that the trans wasnt made to be shifted at high rpms the (6000) but i dont know anyone else who has had this problem i thinking of getting a skunk2 shifter and seen if that will help i have also ordered bushing that are on the way but i dont know if that will help anyone know what it is?? for my 2nd question i have a greddy EVO full cat-back exhaust and it pops sometimes and i dont know what could cause it to do that so please help i what it to STOP poping 3rd and last question im thinking of going with a turbo and i have a aem short ram intake but i was reading some of the other forums and some people where saying someting about if you get a turbo there no point in have a intake what is up with that please remember im new and dont know that much im still learning so if these question seem dumb to you there not to me and just maybe not dumb to others thanks

ok, i don't think it is the shifter espescially if the shop said that it was still ok. chances are either you just aren't hitting your shifts or your clutch may be going, or something in the tranny.

the popping noise i'm not sure about but i hear it happens alot with aftermarket exhausts, but like i said i'm not sure.

as for the intake, when you get a turbo system installed the have to run a new intake and exhaust for it that the turbo will hook up to.so if you are planning to get turbo there is no point gettin intake and headers as they will have to be removed to have the ones for the turbo installed.