If I can put down 5%, retain a lot of my savings/emergency fund, and pay less than I would renting, then it's a win. 

I do want to have an adequate amount saved still for an 'emergency fund', to replace my vehicle one day, and enough to start a small business.

It's also important to note that the bigger your emergency fund is the easier it is to take on more risk.

They may be an emerging manager that is a great operator, but simply haven't been around very long, or it could be a very experienced manager with more acquisitions connections (and presumably good deal flow) than investor contacts, so needs to market to build that network to capitalize on the good deals they are finding.That being said, these "off market syndicators", as you call them, are like "off market houses".  

I have 2 separate brokerage accounts, one basic money market account that I use as my emergency fund since the interest is higher than the bank so I keep very little in the bank, just enough to pay the mortgages. 

But I do have a significant amount of cash reservers + 12 month emergency savings.

That money is best used for an emergency fund and to find your next property. 

Emergency life situations.

In the grand scheme of things, yes, you should eventually replace the windows so 1) They operate properly. 2) It doesn't turn away potential tenants or cause maintenance hassles when a new one moves in.3) Tenants have proper egress in case of an emergency (like fire).Now, windows are expensive, so you'll have to decide how much you're willing to spend, based on how much income the property is bringing in.

I am a first time homebuyer looking to house hack in Chicago and I have an almost 800 credit score, but I don't really have much saved up beyond my emergency fund for a down payment.