speaker placement ...hmm, depends on the size of your speakers and how all the other hardware will be installed.. Will there be a laptop or a "normal" PC inside? What about cooling ..fan(s)?
t-molding - mine is glued on. No routers were harmed on the project

Contact glue (contact cement, whatever) ...
PS. You really should start a new thread on the Project Announcements..
PPS. More pictures and info and we'll be able to at least suggest something...
have fun
