Dear S H,
I'm not an attorney, but I had to deal with a very bad one once. Being disbarred is pretty serious. You don't get disbarred for simply losing cases or if you have clients who complain you didn't work hard enough on their cases. Once disbarred, if you are ordered to comply with rule 955, it means that you have to notify all clients with pending cases, assist with filing substitution of attorney forms, return all files and personal propery, return fees, etc. If you don't comply, you may not be able to apply to have your license reinstated and be punished for being in contempt of a court order.
I personally would be concerned about the character of this man as it sounds to me a likely possibility that he's not very honest. I certainly wouldn't want him representing me in court!
If you tell your friend about this, one of two things will happen.
1) She'll be glad to know and relieved to find these things out before their relationship goes any further
2) She will be furious with you for butting in and taking it upon yourself to "investigate" her boyfriend
You'll have to decide for yourself how close the two of you are as friends. For instance, my friends know, without a doubt, I'd want to know these things about someone I was dating. But, not all women may feel that way. Your friend may be aware to an extent and has made the choice to see past it, in which case she'd be more mad at you than the guy who has gotten himself in trouble.
Only you know whether or not your friend would want you to say anything, and only she can decide for herself whether his "character" is a concern for her or not.
Good luck.