Hah, looks like you're designing a plate of spaghetti! What software are you doing the schematics with? They look great.
Generally looks good to me. What sort of the currents are you running through your heater? Might be better to move your current sensing shunt off board.
If you don't do the digital ins and outs yet, how about leaving yourself solder pads or a header that gives access to +5/ground/p-port lines. That way you could attach a daughter card later.
