I think NPN you have to   to make sense of it.other wise great performing notes since you have cash flow day one is a better bet for a beginner and you align with a great broker who just feeds you the deals.. much much easier and safer.then once you get the hang of it if you want to try the NPN and if you can find one that makes sense.other wise I think its a business and a job basically and needs to be scaled..

If their concerns are legitimate, then address them.

My major concern is the tenants were all accepted just to fill the house and make it look more attractive to a buyer.

The main concern I have, is that the property has asbestos siding, and I have never dealt with this.

Have you read The Ultimate Beginner’s Guide to Real Estate Investing?

What has been posted is enough to be "dangerous," if it wasn't tax season I may be up for a phone call to discuss your concerns further.If you are interested in investing in a syndication and the tax treatment is a material matter I would question whether it is a good investment. 

I highly suggest you to read, "The Ultimate Beginner’s Guide to Real Estate Investing." 

My concern and probably your's is the transition from a paying job to a job that typically takes months before you build your network and close on your first deal. 

I am not sure what concerns you are talking about?

Got the idea from here: https://www.biggerpockets.com/renewsblog/2015/01/31/ultimate-beginners-guide-real-estate-wholesaling-2/