Very small risk with not having a contractors license. In fact ….the government , at least in California, makes sure there are more risks if you have one if you are a small scale operation. Clients have very little reasonable recourse against an unlicensed contractor and not much against a licensed person either, unless there is and escrow or something like that. I believe these are called holding accounts out here, and escrow companies can do them. Dixieline hardware used to do them but I don’t know if they do anymore.
There is the contractors bond and that can help, but not always, and not always sufficiently. Usually the guy who screws up your job did it to enough people before you that the bonding is rendered meaningless.