I didn't purchase all 66 forms so I can't speak the package as a whole.

I've encountered my first payment issue with a tenant.

So that was our first encounter with a probate issue.

I can not find the option for the ultimate package that allows the ebook and physical book.

Ive never encounter one once, nor have I heard that any of my other landlords friends have.

Other issue we will likely encounter is lender likely won’t give loans, especially when that new LLC that we will set up for a joint venture has no history of past flips and they will likely charge a higher interest rate for him.

What challenges may I encounter?

Your goal is to learn over time what a good offering package looks like and how to make sense of the underwriting.  

I was working with a loan officer who is also a BPer and he worked to get another appraiser scheduled while I buttoned up everything in the building, styled it to make it beautiful (great for the pics for listings) and, based on a tip from one of the BP forums, I created a property package with a listing of all the improvements, the costs, the vendors who did the work, comps in the area, the rent roll, pictures of the before and afters, etc. which I handed to the new appraiser when he showed up.

Would I expect to get the highest price selling all 4 as a package or one at a time.