Advice on inherited, rent-controlled tenants demanding upgrades

[Kristy F.]

Hello all, I'm a new landlord and recently purchased a triplex in San Francisco that came with tenants. One couple in the building has been there for 15 years and is paying $1000 below market rate. 

After I purchased the building, I asked them what needed to be repaired. The previous owners didn't seem to do much maintenance for their unit, and the husband gave me a two-page list. I hired a handyman to fix everything on the list, no questions asked. After repairs were done, the wife then asked for new windows and new blinds, and I agreed. Now she is asking for the cabinets to be replaced, window sill to be repainted, and new range hood (current one not broken, just old looking).  

Because they are protected tenants (almost impossible to evict in SF), they act demanding and entitled. The husband is rude to me on the phone and harasses my contractors who are remodeling a vacant unit in the building because he doesn't like construction noise. The wife emails me several times a day with the tiniest issues.  

From a financial standpoint, I know I should do the least possible and hope they leave voluntarily. But I'm conflicted because although I have completed all necessary repairs and habitability is not an issue, their unit does look run-down. Should I keep agreeing to their requests?  I would love to hear what more experience landlords would do in my place. Thanks in advance!