Warranties often have limitations, like they might not cover pre-existing issues, and there could be delays if they require you to use their contractors.I'm not sure if you've purchased a warranty already, but before purchasing a warranty, it’s a good idea to carefully read the fine print to see what’s covered and if there are any exclusions.

Lender A misses this or doesn't have this knowledge and then tells you a week before closing that your rate is changing because the program they quoted wont work once the issue is caught. 

You’ll want to get loans from local banks and credit unions but you may run into issues with more limited features.

I also liked that they are US based as I had issues with my bank with the Finland based Hostaway.Finally, I highly recommend PriceLabs.

Or, in most metro areas, you can obtain the list of permits that have been issued, and see who is receiving permits. 

Your calculations should include utililies and repairs, legals, snow removal, etc.

Or should I just have them install another meter for the third floor to avoid any potential issues going forward. 

For example, I have my house, am building a legal JADU, but later down the road I decide to rent my entire house and buy another primary residence.

The kitchen became an issue towards the end.

Like anything it has to stay balanced but small gestures go a long way in reducing turnover and mitigating many "would be" issues.