In my humble opinion, if you want low, competitive rates, fast closings and great service, work with a broker.I'm also an investor and have been on the other side of the table. 

Your PSF will be much lower than it would be adding one small unit per lot.One thing to note is more than 4 units or more than one ADU changes the financing that is available.  

Sellers are notorious for not communicating any changes in their unit counts to avoid paying taxes.  

To replace your income you need to flip a lot of houses, I'd do the math with an average 10-15% profit margin, because you have to account for some turds.The other opportunity is to change your job and take out the element that you hate.

We have never collected that and it is not a significant cost.Also be very careful changing criteria mid stream, I would only change it between vacancies. 

They also appreciate honesty and transparency so they can make decisions fast without any surprises.Some of the top skills that you can focus on are:Comping: Knowing your comps inside out is a must.Negotiation: Being able to connect with sellers and strike a good deal is huge.Networking: Relationships with buyers, agents, and other wholesalers are invaluable.Also, Get to know your local market being able to talk the talk in your area will help a lot.

They are really changing the shape of the city and it may become incredibly expensive to buy out there soon due to lack of housing.

I think you should change PMs because you have multiple complaints.  

Would you accept a tenant telling you they were going to change how much rent they were going to pay, despite what their lease contract stated?

@Deirdre Lizio see a lot of competiting PMCs start with a pledge of doing it better than "what's out there".Always interesting to revisit them 3-5 years later - after they've experienced the reality of challenging tenants AND owners.Look no further than Evernest: they started out with flat fee management at $99/month and promises of better & fairer service & pricing.Now they're at 10%, capped at $199/month - wonder what changed?