Sounds like a poor investment from the start. That said, expecting free advice on Reddit to save the business isn’t going to work. No disrespect intended, but your dad and his partner are probably the problem. It doesn’t sound like they are good owners. It’s a very niche market and seems to be poorly placed near an existing competitor. All of which indicate poor business decisions. It might be worth bringing someone else in to run the business (or coach them through getting it viable) and consider moving it.

She can sue you. But I wouldn’t worry about it. Small claims court will rule in your favor with photos and shipping evidence. And that’s assuming that the court doesn’t throw it out. If she sues you, she must provide evidence for cause against you. Doesn’t sound like she has any. If you’re really worried, call a lawyer. They can review this in a phone call and probably won’t charge much of anything for it.

The are companies who do this. They will take you from concept to production helping you design, prototype, and patent your idea.

It also sounds like a load of B.S. to most people. I have used this in the past. At least half of the time the customer just says they are willing to wait and asks to be put on the calendar in a future opening. Customers know you aren’t booked into eternity.

I’m pretty honest. I would tell the customer that he’s not a good fit for your service model and he should find another provider.

If you don’t want to be that direct, you can tell him that you are booked with better paying work and no longer taking those kinds of jobs.