Yes, that's correct.

Separate checking accounts not required, but you need to maintain separate books and records.The TREC requirement is correct, but odds of enforcement seem low.

He is correct that you NEVER take the security for last month's rent for that exact reason.

Since I'm doing this myself I did able to correct/complete them.

That’s correct.

Your definition is correct for "legal non-conforming".The "legal" part of "non-conforming" is dropped when it doesn't apply so most commonly people call these units "non-conforming", "finished", "in-law suite/unit", or "bonus unit".Non-conforming: Any property that doesn't meet current zoning requirements.Legal non-conforming: A non-conforming property that was lawfully established under previous zoning regulations and is allowed to continue its use.Based on his posts @Mario Morales is referring to a non-conforming unit.

It might help to give context to their complaints so we could decide if they should have known that.Most MTR guests won't have many complaints if the place is set up correctly and cleaned, so I always expect to handle anything they want, within reason and even a little beyond.

And you are not using the correct terms which is understandable but makes it hard for us to respond.

Correct.

In fact, the USTC has found in favor of the IRS when a taxpayer did not apply the law correctly (what everyone deems the loophole).