Cash-out / Buy-in

[GobiLux]

Hi,

I was playing a cash game yesterday, and after a while someone got busted and wanted to rebuy. At that moment we had a massive chipleader (about 1/3 of the chips) and he offered the busted guy to buy chips from his stack and just give him the money.

The host didn't allow it, because he thought it's not possible to buy-in through somebody else's stack.

Now a whole discussion came up about that issue, and about cashing out for a part of your stack

So my questions are:

1. Was the host right about not being able to re-buy though somebody's stack.

2. Let's say I tripled up during the game, can I cash-out my winnings an still play with my original buy-in?

THX