This is a great idea, I liked the answers I got from the questions I asked and I might do a blog post on it. If you have any specific questions you want asked let me know and I will ask the admin.
The following questions seem to be appropriate:
1. What is their max win amount, and how does it change with the change in the size of the bankroll?
2. Is it possible to divest immediately, and if not, what is the grace period then?
3. What fees are charged for investing and divesting?
I have been following your thread for a long time and i have to warned that this investment on kingdice. With just 1btc invested can make up 7.5% of the bankroll, it seems like the bankroll is very small and the site does not have a strong rep yet.
But when it reaches the size of BetKing, you may already be too late to the party. I'm myself thinking about investing a small amount into their bankroll, something like 0.1 BTC, just testing waters. Let's see how it plays out in the end!