Previous landlord simply answers couple of "compliant" questions and hits submit.

As others have mentioned, you can raise them over time, stagger them, start with non-compliant tenants, handle one at a time, provide a long notice period, take care of deferred maintenance, offer a lease incentive in the form of some type interior upgrade (new lighting, carpet cleaning, get creative).Substitute the appropriate assumptions in the equation above.  

One year I was told that I needed to paint my house in order to be code compliant.

You already established a terrible precedent by being overly compliant to her misbehavior and have now enabled her for further complaints.

If there is a concern about parking, I'd let them know what they need to do and see if they are willing to work around it to be compliant.  

You should make sure they are operating legally, i.e. biz license, OSHA compliant, etc...

When you buy them you can see if they are ADA compliant.

The one time when a S8 tenant became non-compliant, we just contacted her case manager at the VHA and served the appropriate legal notices to the tenant, with a copy sent to the case manager.

Had some minor re-work.ETA: Probably not useful in CA, but in FL, code-compliant windows (130MPH or Installed with Hurricane Shutter/Fabric provisions) can pay for themselves in insurance costs within a few years. 

The agent is really just checking the condition of the asset and making sure we are compliant with new laws like CO detectors and fire safety.