Yes we know Minato has other sealing jutsu but fact of the matter is we know absolutely nothing about them or there workings so how can we even discuss it?look we know he has sealing jutsu other then rds, that for me is enough to say he can seal edos without rds. if you disagree, thats fine we simply do not see eye to eye on minatos capabilities. I will admit that minato loses against edos if we assume he has no other sealing techs.
but if we assume he does, then he seals. i don't think kabuto would use his sound gen right away. if he does he wins, but it doesn't seem likely to me. if he doesn't minato 1shots with ftg.
Other then RDS Minato has no way to kill Kabuto
cuts/stabs any physicle attack/Rasengan < Uzumaki healing/medical skills/oral rebirth/water body/split into many snakes
Kabuto is only 2nd hardest to kill next to an edo tensei itself.