So I have a few parts left most are important and need filling and I will change the characters personality to suit and fit your oc so don't worry :3
Romeo- Taken (secret)
Juliet- Taken (secret)
Nurse- Friend and servant to Juliet but also her source of wisdom.
Vicar- Friend to Romeo and keeps his secrets. Helps him along the way and marry's him to Juliet, also helps Juliet out of her arranged marriage.
Tybalt (prince of cats) |can be boy or girl|- (reserved for blade but if she doesn't it that's fine to) cousin to Juliet, sly and crafty a talented gun slinger.
Dave Paris- Business friend with Julie's father and is in love with Juliet and wants to marry her.
Mercutio- Best friend to Romeo (Taken by fang)
The capulet girls (two roles need to be filled)- Friends with Tybalt, they are all bad ass and good gun slingers!
so thats it so yeah have fun and remember
Civil blood makes civil hands unclean