Rebuilt A 833 front oil leak

As to sticking
Did you suck it together at install with the bolts?
If yes then the M/S pilot is probably jamming in the back of the crank.
If you painted the BH in the mating area there, well that could do it too.
Another thing that can happen; If you hang the trans on the clutch disc during install, cuz your arms got tired, the disc hub will bend, and subsequently stick, or jam if you really hung it.

as to leaking
If the BH is not broken nor welded, I doubt the input-shaft could ever get that far out of alignment. On second thought, forget that idea, lol.
Truthfully, those front seals almost never leak. I would sooner suspect a faulty seal, or some type of error in the installation of the seal, or even, a cracked retainer.
But most likely is that the retainer screws are the source. Those screw-holes are open at the back, and if the wrong screws are used, without sealer, they will leak.

Good luck