non proportional steering from RX possible?
 

I’m doing a quasi toy to hobby conversion on a little 1/24 mini cooper for my kid and wanted proportional throttle without having to deal with mounting the servo. If I were to connect the stock steering DC motor to the + and – of the servo port on the RX would I get full left/right steering using the stock return spring to bring it back to center?

No i don't think that will work. hooking it up like that might cause the steering motor to turn in one direction only. you need the signal wire to tell the steering motor witch way to turn. the toy grade steering works because the small mobo in the rc tells the steering turn left or right when you do.
If you hook it up to just the rx's pos and neg then there is nothing to tell it left or right. so i will only turn one way.