are there any compabitility problem with VCD burning when you change the GOP setting in the capture software?

I know changing GOP on the PV231/231 yeilds better quality so I figure it might improve quality on other cap hardware also.

I don't really know much about GOP. can someone answer these quesiton for me?

1- will changing GOP have effect in filesize?
2- what is the best GOP setting for say fast mostion and slow motion video?
3- is there any other side effect to changing GOP? maybe give some video editor or VCD burning program problems?