For example if one partner brings the 20% down payment and the other will do the labor for renovations then what would be a reasonable split be.

Generally, the coverage of the policy will state; “The coverage of this policy shall continue in force as of Date of Policy in favor of an Insured after acquisition of the Title by an Insured or after conveyance by an Insured, but only so long as the Insured retains an estate or interest in the Land, or holds an obligation secured by a purchase money Mortgage given by a purchaser from the Insured, or only so long as the Insured shall have liability by reason of warranties in any transfer or conveyance of the Title.”

Reason being: most states you cannot do PM without a license.

Is anyone else aware of reasonable alternatives?

But I am looking for a local CPA.I see no compelling reason for that. 10 years ago, most of the local clients of my firm liked to come to our Houston office.

The reason for this is simple - you're just transferring debt.

If the loan is being paid the seller/previous owner has no reason to want off of the loan.

The reason is that one wants to be able to properly avail themselves to the laws and protection of the corresponding state where the property lies.

It helps to know that it's reasonable to break even or have a small cash flow on a good property in a good neighborhood with expectations of appreciation and increased rents and call it a "good deal". 

By the way - for the same reason the 1st position lien holder will be uneasy with 100% CLTV, as a buyer I would be uneasy with it as well.