if the fee should be there for protection, I would be more in favor of a 7 days median price. last 3,5 days + future 3,5 days.

This makes manipulation super difficult and expensive. The 5% looks to me like a random number. Why not 3% or 1% or 0,3%?

1000$ = 50$ fee

10k = 500$ fee

100k = 5000$ fee

IMO this fee is not competitive with any other stable coin in crypto or regular fiat money.

No value here

Value = Benefit - cost.