Okay, I'll jump in...
Shaun, hello!
Greetings from the world of pro drone flying!
Okay, you've asked a zillion questions. Mostly I think you've done some online research and have been seduced by the "buy and fly and make money quick" image that people like DJI and Uneeq want you to have. Kinda like Nikon and Canon - "buy this camera and you will be Spielberg, without any fuss or muss! Instantly!"
I think you see where I'm going with this.
The reality is, those good folk are doing what they do - sell you drones.
What you have to do, is try to make money from flying them.
Easier said than done.
Yes, you can, of course, compete on the craigslist market with the kids with Phantoms, and do weddings for $50 a pop.
That is making money, and that, technically, makes you a "pro drone flier", at least in the eyes of the FAA, who would require you to get their 14CFR part 107 certification, plus full insurance coverage (no, the FAA doesn't require that, but your clients-to-be should).
Okay, so now you did your online courses and you spent your money and now you have an FAA certification. It's a paper test, theory only, unlike in other countries where they actually make you take a flying test to ensure you actually know how to fly your drone. But relax! This is America! You can set the drone to Auto and it will fly itself!!! Yay!!
Not really. But let's just skip over the weeks and months it takes to get even the most basic of flying skills for aerial photography and cinematography down, let's forget about the skills of photography and cinematography themselves - which are still all valid skills that need to be learned, despite all these little black or white boxes with their AUTO settings...
So why do people complain about the "needless" complexity of the 107 exam? Because it's in several parts, basically, and only one of those parts has direct implications to drone fliers. All the others refer to pilots and fliers equally, it's the same parts that all other pilots have to take.
But but but but
I'm not a REAL pilot, I just want to fly DRONES!!!
DRONES are toys, right? Not real aircraft!!!
Welcome to the land of teens with Phantoms.
So far we've been pretty lucky. Most mishaps with drones have been into trees, flyaways, crashes-on-takeoffs, and only very few incidents have been recorded with mid-air collisions with other aircraft or crashing into people.
So far.
A drone crashing into a person should be treated just the same as a car crashing into a person. No doubt about it. And,
according to this article in the Wall Street Journal, it already has been.
Okay, so you get through that lot, and buy yourself a very small Hubsan X4 or Nano XL and fly your patterns, walk-the-dogs, nose outs and nose ins, and really practice. That's at least a battery (around 5-8 minutes on those baby drones) a day, every day. That's how I, and a lot of other pilots, recommend you start. You didn't start riding a bicycle by watching a Youtube video and going "cool, I can do that", did you? Hope not.
The other reason you start small is it's an easy and inexpensive transition from the dream ("you can FLY!!" The drone flies itself!! Just hit this button!!! Yay!!! Oops... where's it going? Flyaway!! Bad rogue drone!! I want my money back!!!") and the reality. Flying ain't natural, and it ain't easy.
And remote flying is, if anything, harder than real flying. Just wait until you lose signal or GPS or vision or any of those deluxe cruise control dealies in the middle of a flight if you don't believe me.
And be prepared to crash, lose drones, all of that, and often, in the beginning. Which is why people say start with the baby $50 drones. Then move up if you can live with the technology and the hassle and the repetition and the boredom/terror of being a pilot. Try it for real and see first.
Then look around and see who else is in your area, competing with you.
There aren't any full-time jobs flying drones, except for in drone companies. There aren't any degrees in drone flying (yet, but give them time), only certificates.
The full-time jobs (many of which do require degrees) include fire spotter, agriculture mapper, construction monitor, geological surveyor, power grid inspector, and any of those professions that, as time goes by, start to use drones instead of putting humans up long ladders or down deep holes just to take measurements of things.
So if you're already into construction, then get into that trade, site inspector, surveyor, quantifier etc., and bring your drone with you. That will be your full-time professional gig that then will allow the occasional wedding, music video, real estate shoot's few hundred bucks a shoot to earn you your jam instead of you having to worry about how you will make your bread and butter doing this.
If you're really into drones, and you really want to get a degree that will make you a full-time drone person, then I'd suggest either avionics or computer programming and/or hardware tech/development. Degrees like that will make working for a drone manufacturer or a drone software company a shoo-in, pretty-much. There are many, many software and hardware developers who thought designing drones and drone systems was easy - only to spend over two years just to get the thing to hover without moving. Looks easy, right? See a trend yet?
As to what drones to fly, I'd get a bunch, fly them, work them, shoot shots, then sell the ones you don't like and keep your favorites. Questions like "which drone is best?" are best answered like this - what's the best? A knife, a spoon or a fork? Or "which car is best?" A Ferrari or a 16-wheeler?
Kinda sorta like all those endless discussions about "which 4k camera is best?", right?
In the end, it's just you and the knowledge that's in your head, and in your hands and eyes. That's about it.
We'll get to the business side of things later, if you want.
JM2c, HTH, YMMV etc.
Best
Chris