Narrowing down the options will probably come down to comps and city/neighborhood specifics; things like permits.Any good suggestions for finding out how long permits are taking in certain areas?

I’d suggest you dig into the numbers, compare it to what a regular sale would give you, and talk to someone who specializes in this type of deal.

I'd suggest a rental verification as well.

As I explore the neighborhoods in NW Philly, any suggestions on reputable agents with experience in those areas? 

I would love to hear more, and dive deeper into suggestions with a little more info.  

The mold remediation companies should have the skills to identify the source, suggest a solution, and give you a bid with a guarantee of their work.

I suggest focusing on building your "Core 4" team—agent, lender (one who can finance both the purchase/rehab and refinance is ideal), contractor, and property manager.

I would suggest keep learning and dig deep on the one real estate strategy you selected to pursue. 

I'm looking into 6unit apartments or any other suggestions near Chicago that I'd consider. 

The heck with all these suggestions.