CA Realtor here (Orange County). I never have my buyers sign the exclusive agreement. I know some realtors do. To each his/her own, I suppose. I have always been of the mindset of not needing to force a buyer to stay, my quality of work will speak for itself.

If you really want to cancel, there's a good chance they'll let you without too much struggle. Otherwise, you're a headache (in their mind) and they'd be better off spending their time somewhere else (time is money).

Since this is the realtor who showed you this property, even if they release you and you go with another realtor, this realtor could fight for at least some commission based on "procuring cause" i.e. "I caused you to procure/find this home so I get the money!" Just food for thought.

It sounds like the issue is your realtor is afraid to use this phrase "I'm not sure, but let me check on that and get back to you." Truth is, we don't know it all, but we have a hard time saying this because we don't want to lose the client! I've worked with very experienced agents who still need to check with their broker, call their association, ask an attorney, do some research etc... This doesn't make them a bad realtor! It's a lot to know everything, all the time, in a vast and ever changing industry. But a realtor who is honest and advocates for you in their research is better than one who pretends to know when they don't (how do you trust what they're saying?). I have the "insider" resources to get the RIGHT answer, and am usually just double checking what I already knew to be true, but I have no problem saying I don't know, then delivering a thorough and accurate response as quickly as possible. I only say this gently to not be too hard on this or a future realtor if there's one question they don't know, we're doing our very best and always learning :) It doesn't necessarily mean they're not the right fit for your situation.

Good luck!