Being a startup with an innovative idea, how far(safe) to choose mentors from same industry, who are actively doing business...???
No matter who you choose, there is always the possibility that they will take advantage of you. However, someone from the same industry who is willing and able to be a mentor will likely be able to provide you with more relevant advice for your business in particular.
It's a common mis-conception that other people are prone to stealing ideas. Yes, it does happen, but ideas really aren't worth much without execution. If you're providing a solid execution, it's more likely that someone interested in edging in on your business will try to do so with you than against you.