How far have you got it stripped down? Are the top swivel pin retaining bolts loose? Once you start stripping everything gets loose quickly until it's all back together again.
Was it loose before you started? If not then it's probably ok.
As for replacing anything, while you're down there as it were!, you could replace all the bearings, depends how far you want to go, and how worn anything is. Up to you really! I'd do the swivel bearings if you're doing the seals.
Check the wheel bearings but should be ok. Put it all back together and get the swivel preload set right and all should be fine...