If I was making changes to the original characters I would make Data a female...it would balance out the 8 main characters...
Picard-M
Riker-M
La Forge-M
Worf-M
Troi-F
Crusher-F
Yar-F
Data-F (Instead of M)
Then there would be secondary characters like Wes-M, Barclay-M, Ro-F & Guinan-F.
Plus you can have an interesting friendship with Geordi...Data being female and all...not to mention even more interesting relationship with Yar if Data was female.
I must be channeling
Gaith.
