Thanks, hiran, that does provide a lot of context.
If I can offer a way forward, then I think the issue is less to do with content and complexities of the keyconfig.plist file (and there are issues here), and more to do with the gulf that exists in the documentation between the core game functionality and all the custom functions that OXP's provide.
Almost from day one, the advice to new users has been to start with the core game, and then add OXP's to the game slowly, so that the changes to the game can be noted and easily identified. However, with the advent of the expansion pack manager, I think we can say that for 99.99% of players, that is unlikely to be their experience. The website is encouraging players to download things, and the assumption in that encouragement is that the players will either (a) know what they're doing, or (b) know where to go for help (ie the forum). But I have a feeling that we are only seeing a small portion of players register on the forum and ask their questions.
The upshot is that the core game is doing a poor job of explaining some things that OXP's are taking advantage of (MFD's and primable equipment being the main examples). Just looking at the Oolite reference sheet with fresh eyes, I can see a few items that are possibly wrong for non-QWERTY keyboards (eg Shift+\ is the "|" character on my keyboard, and that is the key that is assigned in the keyconfig file, but is Shift+\ the same on every keyboard?), I can see some things that are inconsistently named ("special equipment" is mentioned a few times, although my feeling is that everywhere else in the game it's called primable equipment), but the biggest gap is that there is an assumed knowledge about MFD usage and special equipment usage in the documentation that is never addressed. Coupled with the fact that OXP usage must be the assumed starting point for the majority of players, that is a fundamental flaw in documentation.
There is even a naivety in the reference sheet when it says
This reference sheet makes several references to 'OXPs'. Oolite eXpansion Packs can add extra missions, equipment, ships or change the game mechanics. These packs are not part of the standard game and will not be covered by this sheet. For more information on them and how to install them, visit the Oolite Wiki.
So I think the time has come to embrace the OXP situation a little more comprehensively in the included documentation. I have some ideas I'd like to work on to expand the reference sheet and try to bridge this gap. It shouldn't take long to knock together some concepts and share them here for discussion.
As an additional goal, can those with non-UK/US QWERTY keyboards have a look at the Oolite Reference Sheet keyboard guide and point out the key combos that don't work in your environment? If nothing else, if we can identify the problematic keys, we can highlight them in some way on the keyboard guide and provide some more commentary to help players overcome them.