Guys,
Can 100 uBTC Tickets be used to enter 25 uBTC events or they're working only for 100 uBTC events ?!
If so, do you will able to reuse remaining credits?
No, you can't use a 100 uBTC ticket for a 25 uBTC satellite tournament. Some tickets will be for specific tournaments and they can only be used for them, but some of them can be used for any tournament with a 100 uBTC buy-in. This is usually described in the "comments" section when registering for the tournament.
Tickets are like vouchers. Let's say, you have a voucher that allows you to buy $100 worth of food at any restaurant or fast food place, you can't go in, buy $50 worth of food, and expect to have a reuse available for the same voucher.