We have everything in the Bonus terms + Site terms, if something is missing you can chat with the support 24/7.
The FAQ section is usually out in the open on many sites which is why I advise creating a separate FAQ section instead of bonus terms and site terms since this could leave players confused initially(Happened to me). Tried chatting with customer support regarding this issue, but no one was available at the time.
About the phone, its not a must, just for communication by SMS, not have to validate it.
Didn't know that it was optional. Good to know that.