@Greg San Martin good summary. I’ll add:
1- regarding earthquake risk, I’ve given that a lot of thought too. My main conclusion is that I only want to hold properties that are, A- not on/super close to the fault lines (in SF I’m about 7-12 miles away). B- seismically upgrade my properties (sheer walls, anchor bolts as a minimum). C- make sure I’m not on landfill. Given that, I think I’ll only sustain damage in an 8.0ish earthquake. Of course all bets are off if it’s 9.0+, but that’s unprecedented for this area. That starts to speculate along the lines of getting hit by a massive meteorite, earth spinning out of orbit, etc.
But yes, I hear you about diversification. A year or two ago I gave some thought to selling a building or two, and 1031 exchanging into commercial NNN out of state. But I didn't think it was worth it, and I didn't feel that NNN was attractive enough- the safest had middling returns with little rent upside on long term leases, and the more aggressive ones had either short leases and/or riskier tenants. And even back then, the security of NNN was suspect in my mind, given that formerly huge companies like toys R us, Sears, Blockbuster, etc. have gone bankrupt. Of course with corona, the security of NNN has been further shattered. Don't get me wrong, someone who is well versed in commercial can probably still find the good properties today. But that's not me. I know San Francisco residential very well, not out of state commercial. So basically I'd rather deal with the devil I know, as I have so many work arounds in my war chest, given all the experience I have in this market.
2- what exactly is the process for condo conversions in Berkeley? I only know SF’s, as I’ve converted several of my properties, and yes, it was definite worth it (though lots of nuances to delineate.)