Can one use the A7 Commercial for multiplayer networking and also use A8 Pro for other programming?
Not quite sure what you mean, sorry.
The A7 and A8 network functions are pretty much the same, although some stuff like session_open/... is available in A8 Commercial (and Pro) while it was only available in A7 Pro, not in A7 Commercial edition. The number of players in the Commercial edition is limited. There may be other limitations as well but I cannot remember any right now.