There are so many different applications for drone usage, the sky is literally the limit! I get requests all the time from various other industries including real estate, farming, telecommunication tower construction and more. Sounds as though you've got a great background to easily incorporate some drone work into your portfolio. I like the business model of finding a specific niche focus and being known for that specific industry as opposed to trying to cater to the broad market. You mentioned videostock, which is another way to easily generate passive income from your raw footage and/or photographs. I've experimented with a few platforms, but haven't spent a lot of time on it. The royalty payments are fairly small, but on the plus side, you can sell the same footage/photo an unlimited number of times.
Regarding my videos, I often just film in the default setting, which usually captures great footage and requires less post production work. At the recommendation of one of my partners, I've started filming some projects in the DLog/Raw format which creates a flatter video, but allows for much more versatility in post production. As always, I'm still learning and adapting as I go.