Considerations as an "independent contractor"

Howdy all. I need some advice, and this is my first post. If it's in the wrong place, I trust a mod will move it. I know, it's long, but I wanted to cover all the bases.

I was a school bus driver and have a class B. I'm considering getting a class A, but I'm not really sure I want to spend all the hours behind the wheel with the pressure of a deadline, and I'm not sure I want to be hoofing freight around the city and navigating traffic in a truck / trailer. I have a side gig from when I was a bus driver, and my 25 hours a week on the bus worked great. I would have no problem driving part time, but I'm guessing part time class A jobs don't really exist.

As I ponder this, I've come across a job that intrigues me, but they're hiring as an independent contractor. There's a number of financial implications that I need some advice on before I go talk to them. The company produces electronic equipment in the Pacific Northwest, and it needs to be transported to locations in Wyoming. They have plans to expand business to Texas and Oklahoma. The equipment is built into trailers, and they are looking for someone to deliver these trailers using their non-CDL truck. I assume it's a matter of drive the trailer to Wyoming, drop it, and come back with an empty truck. The job listing says it's "as needed", so I assume it's not full time driving. That works for me.

There's a few questions rolling around in my head, and my only point of reference is a job I had 10 years ago traveling all over the west coast for a company that contracted to large national retailers to set up their new stores. I'll reference that in my questions, but I have no idea how that compares to the trucking industry.

Would I want to be paid by the mile, or the hour? I assume mile, but it's worth asking. Considering that I'd be on a 1099, and responsible for my own taxes, what's a reasonable per mile rate, also considering that I'm driving their truck? At my past job I was paid $8/hr travel time plus 32 cents a mile to drive to the job in my car, usually 750-1000 miles.

Google maps says the trip is 19hrs, 1300 miles, each way. Obviously that's best case, assuming I'm going the speed limit the entire way. Realistically, the route from manufacturing facility to destination goes through some mountain passes where my speed is going to be substantially slower. I can't just assume it's going to be two 10 hour days. I'll be in a hotel at least one night, but should I plan on two? Then two on the return? And one night at the destination? Or is this not something I'd have to worry about at all because federal regulations will determine how far I can go before I'm done for the day? Does it matter that it's a non-CDL truck? My school bus experience didn't cover these issues.

For my past job traveling, one company paid for the hotel, and another company I worked for just gave me a per diem and left it up to me. I prefer the per diem because (at the time) it was considered reimbursement, not wages, and therefore not taxable. I always made money on my per diem. Is that still the best way to go? What's a reasonable amount these days?

How should I account for the possibility of down time away from home? Let's say I'm in Wyoming, and they may have me go to Texas, but they're not sure yet and want me to hang tight for a couple days. With my side gig, I don't mind being gone for a short while, but I'm not keen on the idea of sitting around Dirtville Wyoming doing nothing for days. I don't want to be completely at their mercy because they're only paying me by the mile. In my past job, if we got stuck sitting around because the company we contracted to had screwed up their timeline, they paid us a daily rate as sort of the cost of having us on standby. Wasn't a whole lot, but better than wasting our time completely.

So based on my past experience, there's a lot of stuff I'd be inclined to write into a contract, but I don't know what's relevant to this job, or what I could reasonably expect to be common in an industry I know nothing about. Any input you could give would be helpful, and if there's considerations I missed I'd appreciate you pointing them out to me.