What Should I Do?

I have  acquired some horses a bit ago and want to ask you guyz opinions before I get too attached. I got these horses, I honestly cannot remember if I bought them or by chance found them all in the RC. First I found Snicker Doodle and she was pregnant, so I went ahead and bought the father Mystic Comet. I then later found out after getting her that she had already had another foal before so I adopted it and the father, so baby Doodle Bug, and papa Celestial Shark were added along. I love me some cream modifiers so I kept them. Do I give them the chance to be great horses and just keep raising their stats? Or do I raise their stats with selling them in the future? Or just respectfully stud them out until they die? I'm scared I'll get my stuff crossed one day and their lines will come back to haunt me. 

Pretty much all my other GV's are RC-foundation lines so I wouldn't want them to intermingle with that. The fathers have  some of the same horses in their pedigrees grandparents/g-grandparents lines.

I'm trying to breed for pangare, so I would be interested in them as studs/sales later on, if that helps?

or you could always keep them and geld them/not breed the mares if you don't want to keep using their lines?