I am sure that a lot of you have been in the RE industry for many years and have experienced market turns for the better or worst.

In some cities, you can get away with an all-in cost of under 50k, but the issue is that will almost always put you in the worst parts of the city.

At worst, you can position it as a backup offer.You can be as suspicious as you like, but I can't imagine a situation where the seller / seller's agent would reject your offer if it was actually the best.  

On top of this, I'm considering purchasing another home in which underwriting (maybe 3-8mo from now) would probably want me to submit a current signed lease.I know I've committed the ultimate mistake by not having them sign any lease, but any advice as to what next steps should be would be appreciated.

I would also start preparing for the worst and you will need their emergency contacts.

Right on, I had used realtor recommendations in the past and it was a mistake I was able to bounce back from but will not be making again.

There are 3 mistakes in your calculations- The first- With over 100 units your colleague should be able to negotiate a better rate than 10%. 

That way can model out worst case situation and see what it looks like.

I feel the worst part of COVID is how it has created further division in society and is turning into vaccinated vs non.  

If one makes a mistake, own up to it, rectify it and move on.Caveat: Consult proper legal counsel for specific advice as it pertains to your plans.My intent here is simply to provide some general basic understanding and at least provide a road map as to what questions to ask and what issues to explore.