Your agent might be able to sue you for fess they acquired in good faith effort to sell your property - marketing, includes pictures etc. this can go into other things based on a procuring cause as well when breach of contract has been established;If you went the FSBO route after ‘firing’ your agent, any buyer that came through that was a result of the first efforts made by your agent could be grounds for a suit of commission as they were the original procuring cause (they technically brought the buyer to your property first with their efforts), if you went on to ‘bad mouth’ your agent a subsequent defamation suit could possibly arise.

They began insisting that they were entitled to rent reduction or outright abatement since part of the space they technically signed the lease for was uninhabitable.

This is because the promissory note that you receive is not considered "like-kind" to the real estate you sell (speaking technically) and it could leave you cash-poor when you try to reinvest in a replacement asset (speaking practically). 

And you should send her a notice to vacate since technically she is on the lease.

Money is not technically earned until it's applied to a charge.

I mean I think technically the legalities of it come down to the fact that you could text on a group chat as she herself has not told you to not contact her, but if you should is another issue.

The names/ages should suffice since the kids are not technically on the lease as responsible parties, just minor occupants.

LOL  I've never heard of that tactic - simply move in before moving them out.If you can get in, and have keys, even if you weren't the owner, technically, you would have as much right to stay as the other squatters.  

I personally have an addition of 2100SqFt in a 'Mother-in law's quarters' with a sperate entrance, yet it's attached to the primary residence, and if I were to sell it wouldn't be financed separately at all- technically two 'dwellings' yet one total property. 

So now the tenant is technically "current".