Control picture settings like brightness, hue, speed, etc. possible?

Kodi does not support fade in/out itself, but you could pre-process the video content to include those steps to effect nice transitions between videos in a playlist. I'd assume content used for advertising or kiosk type use-cases? will be pre-processed to ensure everything is correctly encoded for nice output anyway, so I'd build that book-ending step into my encoding pipeline. See https://donaldfeury.xyz/add-fade-in-an…ts-with-ffmpeg/ for one approach.

Kodi supports play/pause/stop and management of what's playing (or playlists) through APIs. It also has controls for speed, but you probably don't want to mess with speed for good output (again, if you do, do it during encoding). There are no controls for Hue and Brightness in Kodi (or at OS level in LE) - in our opinion (and what's been coded for) those belong to the TV not the player software.

LE/Kodi support basic kiosk/advertising type use-cases, but to do something more professional you probably want to develop a custom Skin that avoids OSD pop-ups during transitions and might need to make code changes to add features, and all the code is open-source to help with that kind of thing. NB: LE does not take on 'paid' projects, we're not resourced for that kind of thing. Kodi is much the same although some of their team are independent developers in their day-jobs and might consider paid work; but there is no formal channel to ask for a quote so you'd need to post in their forum and hope someone 'bites' on the opportunity (it's never guraranteed).