1st you say the Shaft is warped and now you say its just the oil seals ? well which one is it really ?
2ndly… (I was told by Herman @ Cherry Turbos) if you split the housing to replace the Seals then their is no question that it should be re-balanced. NOW many people (on SON alone) claim you can replace oil seals no problem without re-balancing the shaft. Myself, I’d take the word of a professional turbo rebuilder vs kids on a forum but to each their own…
I would recommend calling some Shops and getting 1st hand information from a professional who does it for a living (you’ll always get mixed reviews from a forum)