Actually, vtir comes with both the y80 and s80 gearboxes. Just no lsd in the s80 from the vtirs. Most people would think s80 gearboxes came from type r's only, but they also came in the Vtir.
jdmyard should have some dba prelude rotors. Im sure they can redrill for you aswell but they are moving atm so that might take abit longer. if not, ebay will have some.
^ wider fronts yes.
Roll your guards and get a camber kit for abit of camber. Maybe a set of coils drop the car abit and to stiffen up so your guards dont eat up the tyres
Yeah thats a heater hose, just replace it and maybe just buy an extra bottle of coolant and flush the old coolant out. Should work fine after you replace that house though.
Ive gone down this path, not in a dc2 though. It was in eg sedan i had last year. Acceleration is better then the s80 vtir gearboxes. U can also give stock dc2r's a run just to giggle lol