bob.lists> Do I just go ahead and register my domains using my (existing)
bob.lists> Netsol registered hosts (ns1, 2 & 3.raha.com) or do I need to do
bob.lists> anything else before I can use them?
You don't need to do anything else.
bob.lists> "Other" domain names aside, any problem with transferring
bob.lists> raha.com itself to OpenSRS but leaving the nameservers
bob.lists> registered at Netsol?
Control of those nameservers will transfer to OpenSRS as well
automatically. However, the host record will still be available at NSI
(i.e., the NS####-HST record).