I am new to the rental game, kinda.

Not sure what your short term rental regulations are for your area, but if HOA allows, airbnb could be a great way to acquire short-term, mid-term, or long-term roommates.  

I own 3 properties and rental arbitrage 1 more with a net income of $400,000.But I am a newbie in LTR. 

@Basit Siddiqi is exactly right that Philadelphia / NJ has some unique reporting headaches that are often screwed up, so whoever you work with, gauge their experience working in numerous jurisdictions, or their teams access to those subject matter experts.Those in the construction world and rental world open themselves up to some substantial opportunities from a tax planning perspective, but also need to be sure they thread the needle carefully on the real estate professional rules to actually qualify for them.

What documents do they require, what credit scores do they allow, how do they verify previous rental history, etc.?

Don't be afraid to negotiate, particularly if you have a lot of rentals.4.

I'm curious, Is this PM out of touch with reality OR on how rental property owners, that don't self-manage, feels?

I could raise their rents to market and recoup the cost of the repair, but honestly, of the rentals I own, only two have AC.

Do you have all rental income coming in one LLC acocunt?

You got bad advice from your prior accountant.You received rental income and it should have been reported.it seems like maybe he was lazy and/or doesn't understand rental concepts.The only exception is if he is paying 'under-market' for rent in which case the property would be considered personal use.I would fix the issue and charge him market rent.