You wont screw up your tune by removing the silencer. It really doesn't make a difference, more for sound than anything.
Why would he need an Sti intercooler? He has an STi...
If you are running in AutoX I would decide what class you want to run in before modding.
With the full TBE and tune you will be in BSP, which is a tough fast class that you will not have a chance in without some suspension work, but if you are just out there to have fun then that really doesn't matter.
02 rex is gone.
I defected to an evo :)
Evo is gone :(
Now I got nothing.