Absolutely! We're still in active development, and we encourage our players to let us know exactly what they want, so that we can make the best product possible.
Here are some roulette features that I would find useful. I am not a gambler, and this is really just a matter of personal taste, so take it with a grain of salt.
1) I am colorblind, so red kind of glows against the ever-so-slightly greenish blue history backdrop. Not a HUGE deal, but after a few hours it becomes noticeable.
2) Introduce empty roll feature (no bet). Roulette brings out superstitious tendencies in even the most rational people, and I think that if you keep roulette logs you will probably find a lot of single unit dummy bets.
3) Single repeat+spin button would be nice, instead of having to click each button separately (but I guess this can clutter the interface a bit). If not, then at least swap the double and repeat buttons, so that one can repeat, double and spin in one motion (left to right).
4) Invert bets feature. This is the most useful addition that I can think of. If a superstitious gambler (i.e. most roulette players) see 18,27,18,27,18,18 then naturally the desire is to be on everything except 18 and 27. This involves clicking on each number repeatedly. (Unless the numbers are on the same row or in the same dozen, in which case you can bet 12 on each row/dozen and fill the other numbers with a single unit, and then multiply through by some scalar.) Either way it's a pain to do this each time. It would be great if you could either fill all outside bets in one click (with the base bet amount) OR place bets wherever you like (e.g. 18 and 27) and then invert bets by betting on everything but the selected numbers. This would save more time for scenarios like the one I described. More time saved by gamblers = more spins per minute ... PROFIT??
5) Half button beside the double button. Blackjack already has this, so why not roulette? Sometimes a betting strategy reaches its limit, and you only win half your money back, then one may decide to take a few steps back and keep trying, rather than reset to the starting bet. The other reason is that sometimes you might be trying to distribute the max bet equally among a bunch of different odds. For example, if betting on everything but 19-24, one would place 12 on first dozen, 18 on 19-36 and 1 on zero, and then double through until it gets to the limit. With a 1000 unit bankroll, you end up with 384, 576, 32, respectively. But now suppose you also wanted to bet a separate line on red, but you only have 8 units left. It would be convenient to be able to half, and then place the remaining bets.
6) Insurance feature. Insurance on even bets would be basically placing a bet on zero. But the size of the bet depends on the even bet wager, and requires a calculator if you want a fixed payout. This can be pretty annoying. For example, for a 200 unit bet on red, the insurance would be 200/18 = 11.11 (say 12), which would pay 12*35 = 420 if the even bet (200*2 = 400) loses.
This is probably a lot of extra buttons! So maybe you can add an "advanced" panel or something. Good UI design is definitely an art, and it's hard to say what works well without trying it out for several hours.
Anyway, I am not sure how much of this is useful feedback. Just some stuff that caught my attention after messing around with your website.
In that case... keyboard shortcuts!
Yes please, and keyboard shortcuts!