Form for requesting sub to be added

[Watchful1]

Have a way for sub owners to pm the bot with the request and it forwards to me rather than telling people to contact me directly.

[Poolitzer]

would google forms be acceptable? Because using them would probably solve your problem :)

Otherwise, I would go with a special PM format. Like subject: new_subreddit_please: subreddit_name, body: Arguments why or so.