He spoke the language well. 

Avoid "flowery" language that just fills empty space.This isn't a social club meeting: you're speaking to a person who is probably running this like a business and has heard from a dozen other folks just like you today. 

I would speak with your contractor and ask them why they felt it was okay to commence the demo and re-roof without permits and they may be able to tell you what the scenario is. 

Yet, by the simple fact that foreigners are not in the country and might not know the laws and the language, their risk of buying in Mexico is higher than if they would be buying at home, as I acknowledged in my previous reply (and yes, there's a higher risk of corruption and they could be taken advantage of, being a gringo).I'd agree buying in Mexico isn't for everyone and you that you need to do what you're doing even more than you do at home.

I have no time honestly to mind other peoples insecurities and I won;'t adapt my language if others are not secure enough to be spoken to directly.That said it is never meant rudely..

Accounting is the language of business, if you don't know the basics then you really can't talk business.

It covers most of what you need using language that a Landlord and Tenant can understand.Note: a tool is only as good as the one wielding it.

When you learn the numbers of loans, you already have learned somewhat the "languages" of wholesaling, flips, and rentals. 

I'm just someone who likes philosophical and logical consistency and precise use of language 

A house-hack or rent-by-the-room lease will have all the standard lease language but with two big differences:It will have additional language around where the liability lies for the other roommates.