Mr. K. 90%+ of a good paint job is preparation. Sand, sand, sand. The existing paint marks and some of the cracks (more below) should just "go away". You will get several suggestions as to what the "best" primer and paint are, so I'll leave that to those with more experience...
Regarding the cracks. They are probably either from degradation of the previous finish OR a structural problem. IF the area around the hatch is flexing, anything you re-apply to that area will crack again so you should eliminate that flex. A whole different job which may be minor or major depending what the cause is.
It appears your FB access is along the starboard, forward end of the area pictured. I would suggest the incorporation of a non-skid material on that area to minimize slipping. You might use one of the stick on non skid sheets or simply mask off that walking area spread a grit (White sand? Walnut shells?) onto the final coat of paint while it is still wet.