As someone mentioned, the only thing passive about real estate investing is the tax treatment. 

A couple developers we work with skip LIHTC and the tax credits and go the route of impact funds to help alongside other debt and sometimes equity. 

.: What is the average conversion rate for cold calling using software like PropStream, specifically targeting probate, foreclosure, or tax delinquency leads?

There is still a risk: You do not have the right outprice and lose money, your deal goes south due to unfound things when you bought it, then the rehab phase brings them up, and you spend more, and the market changes, which is something that can happen on a moment's notice.

I'm currently building my team with Tax Advisor/CPA, RE Attorney, REI friendly agent and designer first on the list in that order.

Sounds like you've put together a good due diligence plan so far. 

Here is the email received"An internal audit has been completed for STR permits and our records indicate that your STR permit was issued in error due to exceeding the maximum 12.5% blockface density.

Happy to give input in underwriting and due diligence.  

As far as flying (tax deductible too) You can do that and if it's in the states the total trip shouldn't cost you more than $2000 all in with lodging. 

I recommend checking the areas near University Circle for that reason, but there are some spots not far from there that can be rough, so do your due diligence.