My understanding is (this may be incorrect), that MP will take 1/2 of the HE between their own commission and the app owner commission, and 1% HE seems to be pretty standard to me.
It used to be, but it's now 70% (50% for app, 20% for MP)
I would disagree with this. A bankroll investor will need to risk the possibility that a casino operator will run away will the coins in the bankroll, that the seeds will somehow leak, allowing someone to cheat, and drain ~the entire bankroll, that the coins are otherwise stolen from the casino and the operator cannot afford to cover the cost of the theft, among other possible risks. In order to measure how appropriate it is to take these risks, a potential bankroll investor will need to know how much they should expect to earn by taking these risks.
There are other investments that a potential bankroll investor can make (eg investing in a company, lending for margin loans on an exchange, investing in the stock market), and an investor should invest his money in what he believes have the best risk/reward proposition.
Fair enough. What I would do is to try estimate the EV of the investment as a whole (which is a total crap shoot that involves pulling numbers from your ass for things like counter-party risk) and then use that to determine how much I should risk in the investment itself (which itself uses the kelly <3). But lets say I guestimated the total EV of investing in MP at 1 BTC for the year, I would never actually personally "expect" to make that because there's so many variables (I could easily lose the entire investment, or make double it)