So I looked up pricing on the internet.

Not only is it the right thing to do to help them get their legal ducks in a row about knowing SPECIFICALLY what the seller did wrong, ie did not disclose and can prove it was done for the sole purpose of deception to make the sale "smoother" but it can help you look good and have you learn how to avoid in the future (as you say "tighten up your due diligence")It sucks when agents "help" 1st time or largely inexperienced buyers long enough to make the sale and get their commission but then peace out on the client when something like this happens.It It seems like you are attempting to do the right thing which is admirable bc at the end of the day, the court system is the closest thing to a "business police" that ppl can get. 

I am a newbie re investor and I was wondering what all experienced investors use to manage their own rentals? To make it specific: What platforms do you use for your listings? How did you create your lease agreement? ...

Random things like this.I can only imagine if they did allow you to add all the bedrooms, they would make you also add fire sprinkler system and a commercial fire alarm system like residential assisted living. 

I do whole house HVAC systems, not window unit ACs. 

Coincidentally, I had this exact same question when renewing our local STR license as they've moved to a system (unfortunately) where the cost of the license is based on the number of bedrooms.

:-)A sprinkler system in a cabin isn't going to do anything. 

You may consider terminating the lease depending on how much time remains, your skills, the legal system, and other factors.Based on what you've said, I am concerned there's someone else occupying the home or something else is going on.

If you are seeking a company you need to make 110% sure they have the best systems in place and the way they are structured doesn't have any loopholes. 

And yes, the entire argument around wholesaling everywhere is that most laws that are being pushed against it (In the states where they are) are because of practicing real estate sales without a license.I am an attorney, but I don't give legal advice on here and never said I was giving legal advice so not sure where you came up with that, but your attitude suggests you will be part of the 99 percent of bad wholesalers who are out of business quicker than an eye blink.You are asking a lot of questions, which is good, but you should be asking them of local wholesalers in your area, in person, so you can see what they do versus what everyone on the Internet tells you.