I've actually seen people do drawings where they take a pokemon or whatever and make a person wearing a thematic outfit. Sometimes they actually look quite nice. For cosplay, sometimes it's a nice middle ground. You don't have to go full blown character/mascot mode and it gives you a bit more creative freedom. I think the changes you're going to make will be fine. You could jazz it up a bit more (the accessories are nice), but it's not necessary. Cons are for having fun and embracing your inner fan-person. Unless you're entering a costume contest I think you'll be fine.