MC should import data from NFO files, as long as the data doesn't already exist somewhere that has priority. Read this:
https://yabb.jriver.com/interact/index.php/topic,87442.0.html Also just search the forum for NFO to find out more. The *.nfo file must be named exactly the same as the video file, except for the extension, and must be next to the video file. So for DVDs, for example, the nfo file must be named "VIDEO_TS.nfo" and be in the VIDEO_TS folder. This only works on initial import, of course. If you have done that, and don't want to start from scratch (Clear Library and re-import), then just run the "Get Movie & TV Info..." function against the movies. It does a pretty good job, gathering data from Themoviedb.
MC will use jpg and png files it finds in the same directory as video files, if they are named the same as the video file, with just a different extension. If MC didn't find such correctly named and located files, select the records in MC and run "Right-click > Cover Art > Quick Find In File / Cover Art Directory". That should find and use the image files.
MC guesses whether a video file is a TV Show or Movie based on the duration. If you want to be absolutely sure MC gets it correct on initial import, you can use the Auto Import settings for the folder to set the tags correctly. Look under "Configure Auto Import > Folders (add the folder) > Edit > Apply these tags (optional)". Just set [Media Sub Type]="TV Show".
IN Standard View, using the default Views, MC goes from Series to a full list of Episodes. In Theatre View, MC has a structure of Series > Season > Episode like you want. Keep the original Views while you learn MC, to learn from them, and create new ones if you wish to change what is shown. Take note of functions like TVInfo().
https://wiki.jriver.com/index.php/Miscellaneous_Functions#TVInfo Learn what is in the Developer Zone:
https://wiki.jriver.com/index.php/DevZone#Media_Center_LanguagesPeople have used lots of ways to group movies belonging to a storyline. A search of the forum would find them. I use the simplest of the methods. I put the grouping into the Series field, and change Views to show the grouping. So, for example, I have a "Series" View in Theatre View that only shows movies that are part of a series. In fact, that may have been a standard View. I can't recall now. (EDIT: No, it is a custom view.) But anyway, it shows Movies within groups like TV Show Episodes are shown within a Season, and Seasons within Series. So "Alien", "Jason Bourne", "Kill Bill", "Star Trek". "Toy Story" etc. all form the top-level view, and drilling down into any of those shows the individual movies.
Again, people handle multiple DVD Collections in various ways. For concerts on multiple DVDs, the easiest way would just be to enter the disc numbers into the [Disc] tag, and then sort within each disc by track. It depends a lot on the type of media, whether the tracks are all individual or use Particles or other methods to break down a large file. I handle them like simple multi-disc CDs, so all tracks in one folder and named for "[Disc]-[Track] [Name]", but that is because I have ripped the DVDs to tracks. If you still have the full DVD folder structure, they will each need to be in their own folder, which can mean that they aren't displayed in a View as one record (concert). Again, it depends on the View definition. That may need to be a separate thread when you are ready to get the best advise.
MC supports all the standard MCE IR commands. As you seem to be using a Bluetooth Harmony Remote, it should support all MCE commands, plus a bunch more. Search the forum. There have been discussions around using such Harmonies. Mostly good. Some configuration issues from memory.
Backgrounds in Theatre View are controlled by the MC Theme. See "Options > Theatre View > Appearance > Theme". Basically, put a bunch of images files into the correct Theme directory, and they will be shown as background for menu levels etc. I have themes for Dakar, MotoGP, Puppies, etc., and I switch amongst them when I get bored of the current one. It is hard to get bored of Dakar photos though!
You want to see images related to the program being highlighted, turn on "Online Media Slideshow", and adjust settings as required.
Enjoy your MC journey!