yeah that is a seal...may take up the space needed for proper mesh...as far as putting a front stabilizer bar, yes you can...I havent done it to either of my 2 but have the parts to do it ( havent messed with them much since I've gotten my rxb-1)...

as far as the shoes and flywheel Eddie was spot on (as usual..lol)...if your not going to race it ( iffin ya wanna race a himoto get the rxb-1 trust me) ya might wanna stick with composite shoes....