Project 3.4 Camaro

I am replacing my leaking tail seal, got the old one out, just wondering whether or not it would be ok to put just a real thin film of rtv on the interference outer side of the new seal where it pushes in.
Also wondering how likely it is for the seal to just go bad, or if it usually means the slip yoke has a burr or something on it.
Last but not least, I think my slip yoke does have some sort of bump on it, I am uncertain if it should be perfectly smooth or not?, I saw it last time I had the DS out and it seemed more of a casting flaw or something than a burr, but if there is a burr or anything, would removing it via dremel or file be the solution?(with great care ofc).
Just want to get rid of this highly problematic leak for good.

Project 3.4 Camaro

got the DS out and now i remember, its entirely smooth on the slip yoke, except the part that sat exposed for 11 odd years, its got some grime and corrosion and what not on it, but I wonder if it matters, and if it does, what should I do about it?

Floor guy

If the rusty part of the yoke does not touch the rear seal sealing lip, it doesn't matter.
The real fix is to remove the tailhousing, and replace the bushing the yoke rides on. Worn bushing will cause a seal leak.