One powerful method is leveraging business credit cards to purchase and renovate properties at 0% interest and zero down payment.

Well hello there, Facebook friend.

Can anyone recommend an investor friendly HVAC contractor in Chicago?

These are family friends and they trust me.

This approach has not only improved our operational efficiency but also helped us stay on top of opportunities without getting bogged down by the details.Have any of you tried alternative strategies or found other methods that work even better?

I recommend finding someone you trust that can mentor you and help you push through your mental & environmental resistance. 

Quote from @Robert Casper: So I just sat with a friend who spent his career (decades) as a commercial bank loan officer, mostly in real estate, with a retirement career as an independent bank auditor.

But this was in a business friendly state and I don't know the laws in PA very well to you.

Not only did our investors stick with us through the ups and downs, but many doubled down—bringing in friends, family, and colleagues because they believed in the fundamentals of this deal.

Yep, avoid working for friends and family.