My fiancee has 30000 in judgements against him due to credit card debt. can this affect me if he is added to the deed to the home?

Absolutely it affect the home.  Once an owner, judgements will "attach" to the home and they will need to be paid before any sales proceeds can be issued to owners.  Also, if you are not married, the creditor can move to force a sale of the home so that they get paid.