freebitco in is an freewallet btc without secret K and you can generate a new Legacy address each day, with 4.08%APY. in btc over yours depositeds btc s...
on freebitco you can charge out when u want., is clear that not all the time it work fine, but, 95% the time then when you'll charge out, work normally...
The new address you generate is for new deposits, once you have your satoshis earning you interest, as far as I know at least you can't generate a new address to transfer it from one to another within freebitco.in. In fact, if you notice, what you deposit to your deposit address is then transferred to a large address where the inputs from deposits, from many people, are consolidated.
What you are right is that in freebitco.in that amount is withdrawable whenever you want, the problem is that for months there are delays in withdrawals, although they end up being processed.