The main factors influencing value are:What is the current zoning? 

SFRs will rise with the market and there are limited ways to influence appreciation with your actions.  

I know you're not supposed to be able to influence that, but I really don't want them over-inflating the assessed value. 

Argue all you want, but this is real world.So, beyond state laws and local rules of court, you rad buying the influence that I local an attorney has with local judges and commissioners (even their staff).

Also, commercial buildings are more likely to be valued by the income they generate and not as heavily influenced by comparable sales.

I don't get loans from them, and I have considered portfolio lending, but hadn't thought about my other business influencing the portfolio lending.  

You'll be most effective by getting to know the principal, their concerns, expectations, time and other issues, and all players influencing the decisions and affected by any outcome.Suggest you copy and print this post,

The next issue is that some third party, center of influence, reports the matter to authorities, say a Realtor who came to list the property blows the horn, that does happen.

I am a self starter and I would attack my sphere of influence and build clients before I even start under a brokerage.

Without Chapter One or the Introduction of social influences you can't really advance into any of these other areas.