[@Mistiel] For me, one and done characters are good in the sense that a player gets to create and play multiple personality types, as well as backgrounds. Much like an actor on TV. But long lasting characters that are used for multiple stories are better fleshed out in my opinion because a lot more character growth/development can be made with long lasting characters. For me, I love using the same/similar characters because I'm not done telling their stories. One and done characters leave me feeling so unsatisfied. What if the RP dies before it truly starts? What if it lasts a month before ending? What if I want to revisit the same character later down the road, but can't because one and done characters are norm? 

So, to answer your question, I think it's perfectly fine for you to hold onto 3 or 4 characters and adapt them as needed depending on the type of RP you wish to enter. I think a healthy balance is to do one and done characters as well as persistent characters. 

That's my two cents.