There is no reason to not take advantage of lower rates and down payment. 

It opened my eyes to the amazing tax advantages of real estate that i wasn't aware of.

If I ever rent to tenants again, I will not allow pets over 25lbs and will base my tenant selection only on their credit and background checks.

There are some advantages to this strategy but it is also very risky. 

If you intend to aim it at W2 Millennials, maybe a Chipotle would be a good fit.And about the restaurant, the menu drives the equipment selection, so when you say you have bought a restaurant, you have bought a menu.I say this because a restaurant is a unique business, and you might want to lease out the space to a successful operator looking to add a second (or more location).

As you grow and get into bigger deals you'll be forced into ARMs so take advantage of the long-term loan while you can - just my two cents.Also, I'd talk to more lenders and see if you can find lower rates and maybe someone who will go up to 80% LTV on the 30 yr fixed refi. 

I do not want to take advantage of them but want to help them as well as help myself at the same time.Any thoughts to how I can work this where it will fairly benefit both parties involved with low risk for myself?

By starting with a primary you can also take advantage of lower interest rates and lower down payment programs.

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

Our predecessors took too much advantage of that rule and “screwed” us.