While this year has been fun, we are trying to build towards a true long term investment strategy, and continue to grow.Where we live (Upstate/Western NY) real estate reliably slows down when the weather turns cold and the snow piles build.

It's true that, at closing, a buyer is typically required to pay their prorated share of property taxes.

True, there are worse "crappy" houses But just having it sit there for 4 years so far. 

It's true that it's not a lot of time during due diligence to come up with a perfect rehab estimate, but if you're worried you won't be able to refi enough out, you can always have the contractor be more conservative with the estimate.

@Gaby PerezPeople always tell me I’m a natural networker and I usually think to myself something about how I’m not sure if that’s true, I wonder if they are just being nice, etc.

You've got a good path forward planned out here.The one mindset thing I want to encourage you to tweak here is about the price/value of the home -- I see people making this assessment every day and it monolithic and rarely ever as simple as:  the home has been on the market longer than the average Days on Market so somethings wrong (price, terms, or condition).It MIGHT be true, but there are a dozen other things that might be true. 

This is the quick math I put together:Buying my own home = 400k = 10k in buying commissions.Selling my rental property = 300k = 9k in commissions for the selling broker (I account I would need to pay 7k in commissions to the buyer's agent)Buying another investment property = 8k in commissions.Assuming I would split my earned commissions with my future managing broker, in the 70/30 ratio, it means I would earn 19.000$ in commissions just with my own deals.I would appreciate any advice or suggestions on this strategy, it seems too good to be true and most likely I'm missing something. 

Most good deals I see are purchased at 20-30% of the true ARV.

This is especially true here in the Chicago area where we are an attorney close area.

It's true that tenants don't need to renegotiate a lease after sale.