Other PRO benefits include unlimited access to deal calculators and landlord forms like state specific leases.  

You have the advantage of having your brother there and there is nearly an unlimited amount of information available online. 

Or are owners able to offer owner financing for unlimited parcels of vacant land each year in every state?

I'm out of state but I’ve come across a bunch of houses in Detroit that start at $2,500.Now, I’ll be honest, I don’t think any of these homes could be rehabbed even if with unlimited resources.My question is about the land.  

Not the other way around as the 'corporate veil of protection' is still valid while incorporating a business entity mind you.I think you're asking if alternatively an LLC would suffice as a way to organize, but this can easily be determined with an SEC lawyer (even an initial consultation).Your question indicated about ten people involved in this particular business plan and could be covered under the LLC as well in the ability of 'unlimited owners' (people involved)- but again that's where a consult with an SEC legal professional comes into play.There may be things that even your LLC would be involved with that (if you started there) would pop up on the SEC radar- and it seems better to know how to most legally organize from the start.There are various podcasts and books on this topic for folks in your exact situation, but I would consider maybe just skipping those and going for a meeting with an SEC lawyer from the gate- better safe than sorry, and you may be advised an LLC would work just fine for you.

Or a Reg A filing with SEC to raise up to $75 million/yr or unlimited with a Reg D and only from accredited investors.

CAP rate compression is almost meaningless when you have virtually unlimited access to investment capital.My real estate agent put it this way: even if this place only cash flows $100 and it costs $1,000,000... if it doesn't cost you anything (i.e. 100% financed or investment capital), in 15 years you have a paid off asset worth $3,000,000. 

Unlimited potential.

Question: I've seen conflicting opinions on whether or not you should accept unlimited applications and application fees at one time or if you should cut it off at 3-5 and process those before accepting any new ones.

That makes sense in theory, but there is not an unlimited supply of quality contractors.