@Karen Bolyard
As mentioned, being a real estate broker doesn't automatically qualify you for the Real Estate Professional Status (REPS) ---- IRS chose such a bad name. Certainly, working in real estate can help.
REPS doesn't exempt you from taxes... It just lets you take any passive losses that year onto your 1040. I should add, while that's CAN be nice to take losses/deductions, its better to actually be positive and make money.
If you flip, you are considered dealing in inventory, not an investment property. As such, the profits are taxes are ordinary income subject to self-employment tax. Also, if you are intending to flip it and even hold it for over 1 year, its still a flip.
Knowing that, you can only 1031 investment property which it looks like you understand.
I have no idea what hainvg LLC's has to do with qualifying for anything on your post.
i wouldn't let the "tax consequences" drive your business decision. What is the "best use" of the property / your funds / your time? For example, for want of saving x% in tax, you have to spend add'tl time being a landlord and have your funds tied up. Would it be better to sell quickly, recoup your funds and do another deal?
Good luck.