[frizzen]

Smallhaul ha several dozer or bobcat builds that replaced the standard hs645 with the digital version of it since they have a faster transit time, maybe look into those specs for the size you run? Check the channel endpoints, you might not be giving the motor control full range/speed. You might also have a dual rate setting turned on in the tx.

No, that drawing will let smoke out.

All the grounds can just be tied together. Put esc + on a side, put battery + on center, put charge + on a side.

I'm not sure if you're using a 2 or 3 pos switch. You want center off if you have it. One throw connect charge to battery, other throw connect esc to battery.

Li-on isn't used much in rc. Its safer than lipo. You don't generally have much of a C rating, the chargers are kinda weird, and a lot of them have a circuit that bricks the battery after x time or cycles. Hopefully someone knows more about them than me.