Great guy, very knowledgeable and experienced. 

Readers should seek professional advice.

These include accidents (I recently had 2 units destroyed by fire), natural disasters (I have had two units each hit by 2 hurricanes), property management turn over (they sell or stop being as good, I have experienced both), or turn over of team (I am turning over at handyman and I suspect plumber), or just wear n tear of property (slab leak in poor location, sewer pipes rotted out (one unit this month), roof, foundation issue, etc.).  

That said, plenty of successful investors do it without one by working with experienced agents and focusing on building a strong network.

I don't butt into his business and we keep a professional, yet friendly relationship. 

It's also very risky to do 0% down, as even experienced flippers always mess up on budgeting/construction.

Readers should seek professional advice.

Apply the 70% rule to determine your maximum allowable offer, then negotiate and get the property under contract, ensuring your agreement includes inspection and financing contingencies.Arrange professional inspections to uncover any unforeseen issues, using these findings to negotiate concessions or confirm your repair budget.

Did you work with any real estate professionals (agents, lenders, etc.) that you'd recommend to others?

I have a few questions and points, which I'll ask below, but this is definitely a question for a NYC based real estate attorney who is educated and experienced with both evictions and rent stabilization.