The idea is fine, but I dont see the really reason behind it, since IMG can act like you at the moment. They can serve semi-unlawfull groups in their current form.
Trying to leave them and start an own busines could be fine if you change their main role. Until that there is no really reason to make a new group, but this is just my opinion.
About the IDs. Like or not, that is a common rule. Just 1 ID per faction. If you would like to mix them, go and make an official faction where you can make your own ID. Until that you must keep yourself to the 1 ID per faction rule.
InRP you can mix the junker and IMG behaviour somehow, but using multiple IDs in the same faction is a big no.