Is there a security/ deposit hold? If so how much

I think the deposit only applies if you pay cash. Sounds like another person questioned it and did not have to pay. So try it.

$500 deposit for the double bed . They don't tell you that time of booking. They will tell you at time of check in. Very unprofessional

I believe it was $50. However, I questioned that policy at check-in and they quickly agreed not to charge it.

Yes