I voted for BetFlexi domain but when I said the domain name, it sounded a little strange. If I may give advice on the BetFlexi domain name it is better to change it to Flexibet. Every domain name must not only have good branding but also must have a broad meaning in a domain.
Flexi = flexsibel where later the characteristics of your betting site are flexibility towards players.
Bet = bet where there are many games that are easy to adjust.
Because is so hard to find one word .com domain, you must use two words. I would search for domains where first word something unique and yours but second word something recognizable. Like Windice, Bustadice, FortuneJack, Sportsbet
OP I am not sure how is smart to post here your domain name ideas. There are many domain retailers and if they find something interesting he will take it before you.
Well, there are many domain retailers that hunt for good and unique domain names, but from many domain retailers there are still more vocabulary they don't know yet. So, even though they have taken some good domain names, there are certainly many good domain names that we don't know about yet, we only need to think of suitable vocabulary ideas.