Answer to all Q's: Too many questions. Too few facts and documents. Hire counsel to review facts, deeds, title.

Your attorney may file MSJ and plead admitted facts as support for MSJ.

Both you and child have support rights which should be explored with FL counsel at earliest opportunity.

Immediately: -report suspected abuse to law enforcement and APS in jurisdiction in which mother currently resides; -hire probate counsel to file...

Possibly/not. Service by mail not proper in certain types of cases, certain documents.

Possibly. If trust terms permit successor trustee to refinance, you may do so. This is more complicated and way beyond ability of an escrow...

Yes. You have right to file objections. Your attorney can assist in filing objections.

Yes. You may request welfare check by local law enforcement and adult protective services.

Yes. Lender may apply full loan payment to interest before principal.

You need full consult with attorney.