Moreover, I had to wait when they all be counted by BM + wait for tokpie checking and depositing.
Tokpie checking and depositing was very quick from my memory.
You say 10-15% for borrowing. But you don't have to borrow. It's easier just to buy.
Only if you have the money. Quick example: translation stake cost 122$, if a hunter want to deposit his 28 weeks worth of stakes he'd have to collateralize 28*2*122*3=20 496$ what kind of bunty hunter has this kind of money to spare

?
Actually, new bounty stakes depositing is better... it allows to earn more than before.
Only if you have enough money to begin with.
High competition under previous scheme made stakes prices very low (you probably forget it)
No, the price of stakes depends mainly on the project and not if there is a lot of bounty hunters trading the stakes or not.