Does assigning co-host to meeting interfer with or affect the co-hosts paid personal account?

Yes, that is certainly possible. The original host can make another participant either a co-host or pass the host role entirely to another participant before leaving the session. When the host clicks Leave, they should see two options: End Meeting For All or Leave Meeting.  Choosing Leave Meeting will have that user exit the meeting while others can continue on, with or without a host/co-host.