I think the main page is a bit too long now and a tad bit overdeveloped. The Fallout and Wasteland wiki got it right, simple and understandable.
By all means, add/edit anything you wish! Be bold. As long as it adds information to the wiki, it's good at this point.
I know the main page's still a bad excuse of a wiki page right now, but at least the source code is now a bit more clean, there are no more template boxes and the page has some actual underrail-related redlinks to get everyone, including unregistered editors, started.
Are there game files we can look at to extract descriptions of items, feats, etc.?
If you have some sort of XNB exporter, you can probably export most of the game's data.
I thought of exporting all item icons and uploading them to the wiki as 32x32x32 png files. That would be a lot of work though, and Styg might already have them in separate files and/or higher resolution.