If I bought say 50 points. Would I be able to transfer points I rent to my account and then be control over them?
"Transferring" and "renting" are two different things.
When points are
transferred from one owner to another, they go into the pool of points you have in your account, and are yours to do with as you wish. You are limited to one transfer in or out of your account per year.
When we talk about
renting points,that's a situation where an owner makes a reservation for someone else,and is then paid for that reservation. In a rental, the owner makes the reservation, owns it, and controls it right up until the guest checks in. Even if the guest is another
DVC owner, the guest has absolutely no control over the reservation, Member Services won't even acknowledge the reservation exists if you're not the owner.
As you can see "renting points" is a bit of a misnomer, it's really renting a reservation. If, as an owner, you were to rent from another owner (as opposed to doing a transfer), the points remain in the other owner's control - they never go into your account.