Charge - it is worth revisiting this at a later date, especially if you intend to market the casino as a stand alone product, where such charges are pretty much unheard of. Much of the competition does not charge at all for withdrawals, and that includes combined sports/poker/casino sites.
Would scrapping such a small charge REALLY hurt so much that there is "nothing you can do about it". It is something that could put players off when they compare Purple Lounge casino with the rest of the MG stable.
ID - Although not a problem for me, there have been many tales of players without Passports or Photo Driving licences having a VERY hard time getting paid - sometimes it takes months. Although this does not put off too many players, IT SHOULD - if they can't meet the ID requirements, they are going to find it hard going when they make their first withdrawal.
It would be better to ask players who know they have no photo ID to get advance clearance from your finance department BEFORE playing. They could then be told how to get a Validate UK card. I had the impression that these cards were mainly for older teenagers and young looking adults, and enabled them to prove their age when purchasing restricted products such as alcohol and tobacco.
GBP accounts and Leaderboard - well, this one gets my attention! This softens the blow for the 1 charge, as I would not also be hit by Neteller convertion rates that far exceed a $1 charge.
When I see a leaderboard, you will see a new player account
Only on the new PC though, I have given up with MG on the old one.