I don't like shrimp in my betta tanks. The bettas do have a tendency to kill them after a while, and they don't tolerate ammonia well at all...so if you aren't religious in changing water..they will crawl up somewhere and die...which ruins your water quality if you don't find them soon enough. They are messy too..they put out alot of waste imo. Plus you have to make sure you keep Iodine in teh water..or when they molt their shell won't harden and it will turn all mushy and white and then they'll go hide and die.
You said the mother to the cellophane was a crownie..what was the dad, a halfmoon or delta? That's what it looks like to me..somewhat like the crown-moons Yeevie has been after.
Not trying to be rude, but that doesn't even come close to looking like a rosetail betta...that is a very distinct pattern you don't see often.
See how the rays overlap each other..making the fin look scalloped, like the edge of a rose petal.
Beautiful fish regardless. (and the only way to know if you have too many fish..or just animals in general..is if you start no being able to take care of them properly. If everyone is healthy, fat, and sassy...then I'd say you are doing ok with the crew you have.
Personally....I have 12 bettas, 2 dobermans, 7 cats, and a 8 yr old. lol