Having lived in San Francisco all my life I've had many encounters with members of the SF, Oakland, Daly City and some others. When I say encounters let me be clear - it's always been positive. I've never encountered a pool cue or steel toe. I'm not an associate or "hang around" as I don't ride and seldom attend events at the SF Clubhouse. My main connection is that I went to school with several members and worked with another. I've been friends with the guys I went to school with before any of us had drivers licenses - not that it stopped us...
All charters operate independently of each other in terms of business both legal and otherwise. I'm not going to reveal anything that isn't common knowledge but I will confirm a couple things and maybe dispel a rumor or two.
In SF the HA are involved in MANY legitimate businesses that provide members with a steady good income. They own and operate several motorcycle repair shops and sell used bikes. These are NOT chop-shops and for obvious reasons nobody will find anything stolen at these places. That being said, it's not unreasonable to believe that bikes and parts do find their way into members' possession from time to time without receipts. You'll have to go north to places like Shasta if you are missing something. SF HA also owns and operates FRISCO/415 clothing which does a steady business selling not only "support merch" but other shirts, jackets etc.. with catchy criminal phrases. Every wannabe tough guy in the Bay Area has probably bought something from them - it's very profitable. As far as drugs are concerned the SF and Daly City charters are heavily involved in the medicinal cannabis trade. They supply a good number of dispensaries throughout the Bay Area and operate quite a few grow houses in San Francisco. Members also have connections to other narcotics however these are not major revenue streams - if anything a few members may be considered "mid-level" dealers. Speed was a BIG money maker for many years in the 80s and 90s and the HA would supply what was known as "peanut butter" which was a brownish colored amphetamine. Potent but harsh - with the arrival of Sparkle, LA Glass and other types of speed the HA lost a lot of the market share to the point that nowadays only users close to the club by their speed from the Angels. Prostitution - all I know about their involvement in SF is that they serve as muscle, protection for "escorts" and "dancers". They are not actively out pimping or running brothels. Guns are available but if you are not a member or known associate then your chances are slim if a member will deal with you.
Much of the less than legal business of the SF Charter is not conducted in SF partially due to the location of the Clubhouse. It is in an area that thanks to the tech boom is becoming increasingly upscale - quickly. While the Angels may have the safest block for miles (some of the worst housing projects in SF are less than five minutes away)and they treat the neighbors well they also understand that the neighborhood is changing and that one too many calls to SFPD will bring unwanted attention.
As far as membership goes there are a few "hang around" chapters and you'll often see members of these chapters riding or hanging with full patch SF Angels. I'm not sure if they are prospecting individual members or entire "hang around" chapters for possible patching over but over the last five years there are more clubs in the Bay Area and quite a few seem to be Hells Angels "farm teams".
Finally, I don't know about SF being more brutal than other charters. I've never been on the receiving end of anything but a beer and a shot but I've witnessed their handywork. One time in particular stands out. It was a Bay Area thrash metal festival with Halford, Vio-Lence, Testament, Death Angel and several other bands playing so you knew it was going to be a night of "good friendly violent fun". The HA were out in force that night with at least a dozen members and an equal amount of prospects. I'm not sure how the altercation started but during the show a swarm of Angels went into the men's room. They were beating the living shit out of somebody and his friends were trying to get security to intervene to no effect. Almost as soon as it started they dragged a guy out of the restroom - he looked BAD - and they threw him down the escalator - it had not been working all night but was about three flights of stairs in height. Once the victim was thrown down the steel stairs of the escalator the Angels quickly gathered the prospects and left the building. From what I remember it was mostly the prospects that were in the mens room administering the beating. Since it's none of my business I've never asked about it but it wouldn't be out of the question to assume that this was a planned activity for the evening and that SOMEBODY was going to get bloodied perhaps as part of an initiation.