Neu 1512 2d f

I made up my mind...this is my set up...Neu 1512 2 df, MM, 4s lipo, 14/61 gearing. I ordered mod 1 and 32p pinions 5mm, I hope one will work. CCbec. Should I get an RX cap and what does that do? Should I drill air holes in the esc case and add a fan. I'm scapping the stock servos for one 333 0z in, stock ones suck. Do I need any mods to run the single servo? Sorry about all the questions but us newbies to electric need all the help we can get.