Hi joksim299.

1) Bets verification procedure is the same for all games:
Rules - https://cryptogames.io/provably-fair
Verification form - https://cryptogames.io/verify
Bet - https://cryptogames.io/bet/EJBBR47E

2) The Expected return on new 5-reel slots is 97.05%.
10 free spins are given for each bonus round.

3) What do you mean by the gambling feature?