Hi Chet,
1. On occasion, 50%-100% of buy-in, no rake or reg fee deducted from add-ons
2. In the UK it is fairly standard to +10% Reg fee, so for example a £30 tournament would be £30+£3 (£33) which keeps the house fee and and prizepool separate.
Some tour operators do rake the prizepool, as you do in the US, but it is not popular, possibly because it is not sufficiently transparent compared to us being used to a Registration/Participation Fee
Regards
Stu