If you feel ambitious, you could try a BRRR strategy adding additional equity to the subject home and then taking equity out of it to pay off either the HELOC or if you decided to the refinance the primary residence. 

I think there are many reasons, and some of them that come to my mind (subjective opinion) are:1.

Publication 15, Employer's Tax Guide, says only this much:...Payments for the services of a child under age 18 who works for their parent in a trade or business aren't subject to social security andMedicare taxes...No definition, and IRS publications are not really law anyway.

I'm a newbie tooSelf education through books is a conversation between the author (mentor) and you.You'll gain knowledge, connections etc but it takes timeAttending meetups, listening to Youtube videos on subject matter further broadens knowledge base

Seems like a great book but would like to find another book or two on the subject.

If 50% leverage is used, $10,000 cash invested would buy $20,000 of the subject asset.  

Quote from @Timothy Franklin: @Trevor FinnI would agree with your breakdown, but why overlook a potential to run the 91k subject-to with a targeted 6 month hold for flip or 18 month refinance?

It means that you, as the purchaser, cannot close on the purchase of the property until (subject to the terms of the contract) the seller identifies a new asset to acquire with the proceeds of the sale. 

The general idea is that you must acquire an interest in real property you do not already own, and since you already own the subject real property you want to build on, the transaction must be structured so that you are creating an interest in real property you do not already own (in fact, it does not yet exist).

While podcasts, books, seminars, and websites offer general knowledge, you'll buy a specific property in a specific location, subject to local rules and regulations.