There is a lot of good advice here. Consider reading this book as well:
HBR Guide to Buying a Small Business: Think Big, Buy Small, Own Your Own Company (HBR Guide Series) https://www.amazon.com/dp/B01KP33K4Y/
Also consider that there are other opportunities out there. Maybe the best thing you can do is to just spend the time vetting this deal and understanding the risks and upsides, well eventually walking away. There are plenty of other businesses in a similar position, so it's hard to imagine that the very first one you are considering buying is the right one for you.
How many businesses generating 0.5-1.5M in annual FCF have you looked at already?
From this post, my guess is zero.
Buying an existing business is a huge topic that requires a lot of unpacking.
Start by reading the HBR Guide to Buying a Small Business.
It will frame many of the key pros and cons, as well as give you lots of direction on next steps and clarify many of the early questions you have.
Good luck!
Why can't you represent yourself as a team member of the fund? It lends a lot more credibility to say you're part of a team backed by xyz investors looking to purchase a single business, rather than a random tire kicker. Also, are you approaching business owners directly, or going through brokers? The latter will not divulge detailed info without financials.
If you haven't already, pick up a copy of HBR Guide to Buying a Small Business. https://www.amazon.com/HBR-Guide-Buying-Small-Business-ebook/dp/B01KP33K4Y/ref=sr_1_1?ie=UTF8&qid=1489500489&sr=8-1&keywords=harvard+business+buying+business
Barriers to entry are there. But like a lot of boutiquey things, many people would like to run such a business and not strictly related to reasons linked to a good business plan.
May be easier to buy an existing firearms business rather than trying to start one.
This may be useful to you:
https://www.amazon.ca/HBR-Guide-Buying-Small-Business-ebook/dp/B01KP33K4Y