Tricky....dare I suggest independent? x
Yes you should definitely consider becoming independent, even alongside the agency work until you find your feet.
Ask yourself - imagine you had spoken to this timewaster on the phone yourself, may his attitude have come across? 9/10 times it does, and your TW radar goes off. Also, as an independent you can ask if they have requests or anything they'd like to ask over the phone, in which case he may have mentioned BB, then you would've said no and not wasted your time. Agencies can't answer many questions on your behalf, so I doubt they engage in that kind of conversation with the client, or may just agree to things that you don't offer to get the client through the door.