Just transfer the money to your main account, by trading. It's safe.
I made 20m within 2 days, traded too many times, my botted account was banned, my main account still safe.
Jagex will just ban the botted account, they can not do anything with anything related to your main account if you're not doing anything against the rules.
I can not see "Mule is against the rules".
If they ban you for that reason on your main, they would abuse you. And you open case toward them, and they can get fucked.