Shouldn’t be too bad.However, converting the Duplex to a four plex is a much bigger deal, I would seek out some more specific advice to your location before pulling the trigger.

Your offer to partner on a four unit interests me but I am probably not ready to pull a trigger on that now. 

Takes a lot of work and you have to be able to pull the trigger fast, like less than 24hours.Personally, I would not buy right now in the San Jose market based upon appreciation alone. 

In NJ under the Anti-Eviction Act, a landlord cannot impose a rent increase so large that it is "unconscionable", meaning an increase that is extremely harsh or unreasonable. 

She isn't sure about it now but if you pull the trigger and have to spent time out of town working on it I can't see it winning her over for the next one... 

When you have it sighted pull the trigger .

That in itself does not trigger the HA to terminate the tenant’s contract.  

Some make it sound like a full time job, I would say I don't spend more than 2-3 hours a week managing his property, even in the harsh winters of Boston.No LLC costs, etc.

I also spend a lot of time in Detroit for biz, but just can't seem to pull the trigger on that area.

Now, I'm not trying to be harsh, just telling you how it is: as @Brandon Turner and @David Greene say on the BP podcast all the time...the quickest way to NOT find a mentor is to blatantly ask "will you be my mentor?"