Withdrawals need to be "in multiples of $100". Does this mean that I will always have some amount inside that I can't withdraw to my bank? (Unless total adds up perfectly to a multiple of $100)?

Yes correct, so everytime you withdraw, need to be in batches of $100. Like $100, $200, $300. Because you earn interest on the deposits inside, likely the account balance won't be exactly in terms of $100. Probably got few cents and dollars, like $405.22, so you can only withdraw $400. But if u want to withdraw everything, just terminate the policy

You can terminate the policy to get everything out.