As for the customers, there needs to be a demo because this particular project doesn't quite work for consumers at this stage. To begin with it's a SaaS for businesses. Meaning we'll have to pitch it directly to the business at first.
If your solution really solves their problem, they will do it. This happens all the time and I've seen million dollar deals happen this way.
Their inability to be fair/competent is what's breaking me.
No written agreement & they are sending you cash! Wow.
> The problem is that this shouldn't have been so painful for me in the first place
Startups are incredibly painful, especially at the early stage. There are always exceptions, but lots of red flags to what you've described. Most importantly it doesn't sound like your team is committed... But it also seems like they lack the relevant competency in Sales, Product or Startups. You might learn a lot by going down the path you're on, but it sounds like you're going to be learning by running through walls so I would expect it to hurt.
them sending you cash without paperwork? That's more don them. The biggest risk for you is the expectation management and scope to wind it down.
And I wouldn't be hard on yourself if your first try doesn't get off the ground, most startups don't. Just learn, grow and have fun.