Cons: you did stuff on that can get you banned
Pros: Its rich.
You can make it your main if you're not going to keep hacking with it or connect it to any more accounts via trade or gifting. You should let it sit for a month or so and not log on or touch it before switching.
If you've got items you hack on it you need to gift to another mule and not open gifts for two months, then you can gift back, let sit for two months and be as ok as you're gonna get..