Do I have to sign a quit claim deed to a house that is in my name only so the ex can get a refinance loan if I don't trust him?

No.

I am doing reverse mortgage ....Do I need an attorney to represent me?

Put it this way, do you feel comfortable engaging in this transaction without being represented by your own counsel?

Is a partition action the only way to settle property disposition between two co-owners?

Work it out amicably as between the two of you and it will not cost you anything.

Seller left house in appalling condition. What are my rights?

And you saw the house before you closed, it was in appalling condition, and you closed anyway? WHat would have prompted you to do that?

And what precisely is a "subject to" closing?

My mother's name was removed from the deed to her house. How could that be done without all parties involved going to a lawyer?

Only your mother can remove her name from her deed.

Town home

If what you stated is entirely true then your townhouse was not sold.

You would have a competent attorney prepare a Deed , and accompanying documents needed to record, from John Smith f/k/a John Jones to John Smith...

Deed under wife's maiden name.

No, but (at least in NY) if you want to change your form of ownership to a tenancy by the entirety you need to change the deed.

Do I need a real estate attorney to purchase a private mortgage note from a relative / family member?

Not if you know how to do it yourself.