PvP Games is a good idea, but some casinos that provide this game don't get many players interested in trying it, maybe because opponents are not always available because this is what I have experienced when playing games on mobile applications, sometimes there are no players available to play with, but from all that, I hope that your game development can run smoothly and provide something different from other casinos so that there will be many players who are interested in playing
If so, the OP can still add casino games in general so gamblers can keep playing them if they don't want to play PvP games. What's important is if OP can provide something different from other casinos and inspire curiosity in the players, they will come back to try their luck. And don't forget to do promotions because that will make many visitors come to the casino. Maybe allocating some funds for the promotion and planning how long the promotion will last will let them know how the casino site is developing over time.
Yes, this is needed. Not that we don't have an interest to play p2p games but it always better to have different choices so that we will never get bored. I heard on other p2p betting sites, there times that there are no players so the people who want to play will be tired of waiting for someone to come in the room, so having a non-p2p game will be great to those players. Having a dual support of games is something that can be unique and we know that people always love unique stuffs.
Usually, most casinos do only offer non-p2p games. If there are sites who have p2p games, they don't have non p2p games. Promotions is important. It can make the people enter and stick with it so don't worry, each casino do always set a budget for it.