But everything I've ever seen on them is from larger, experienced sponsors.

Any feedback/suggestions from more experienced commercial real estate investors would be appreciated!

Everything you experienced with this tenant, let it burn into memory and let it be a lesson learned.

I have plans and engineering ready to go, but have held off on official plan check as I can't seem to get a consistent build cost. 

Has anyone ever heard of such a thing where in order to replace an existing boiler with one of the exact same model you have to pay an engineer $1,500 for no reason?

Experienced investors (@Gino Barbaro can pipe in here as he did a no money down deal, I think) rarely come across such gems and even then they've put in the time, effort and money into having a system through which they can take this deal without putting any significant capital down. 

Keep asking for different representatives until you get someone who is experienced- the first person I spoke to really wasn't much help but the second was very knowledgeable.You can use USPS for postcards, I don't know about letters?

Since I am not experienced in real estate, I have dozens of questions about filling out the application and no agent or customer service representatives I can turn to. 

If you do a search for Nomad podcast or Nomad classes in your favorite search engine, there about 100 webinars/podcasts on this exact topic and how to do it.

Find a commercial RE broker for anything larger than a 12unit (unless you’re experienced in commercial).