They could learn that FHA will finance up to 4 units, get all their income documentation in place, get their credit score improved to the proper level, get the seller to do the required repairs, get funds properly gifted for their down payment, contest a bad appraisal and get it revised, and think their good to go......then they find out that while FHA finances up to 4 units, they have to be owner occupied, and the buyer can't do that so the deal is dead and all the work was for nothing.

I keep going and having that property enforced it to a whole new level.

I am considering purchasing an 11-unit mixed use (10 residential and one street level bar/restaurant unit). 

If you are still tax positive (not sure if term is correct), check with your accountant to see what other business you can use against the property.Depending on your gross income level and how you manage your property, you may not be able to write off anything on your other income from the tax loss of your property.

We have done very well for ourselves in our properties but want to take it to the next level.

What is your level of business knowledge currently?

.#3 is fairly passive if you have a good turnkey company, good location and a good PM.Of course #4 is all you although you could partner up with someone else.So it comes down to your goals, the level of passive vs active investor that you want to be, your resources(Time , Money, Experience).Your choices will depend on your goals. 

Given your W2 income, early withdraws from those accounts will likely kill you (its taxed at your ordinary income level plus a 10% withdraw penalty).  

The strategy you use really depends on the motivation level of the seller.

I have been working in the construction and real estate market for several years now and Im ready to take things to the next level and get my license.