Once I put a book into Calibre, and make sure the metadata is correct, I delete the original. If there's any important info in the original filename I put it in the metadata. Is there a reason I need to save the originals?
Sure. Softkeys - a row of buttons around the edges of the screen - are how a lot of electronic test equipment works.
In fact the UI can be identical for a device with softkeys vs. one with a touchscreen. It causes a few DOH! moments when you are working with some instruments that work one way and some the other, but this isn't nearly as annoying as you might expect.
You still have to look at the screen though. Unless maybe you could 'lock' the UI into one mode (with no sub-menus), which might be a good compromise for vehicles.
That's how https://tweetdeck.twitter.com/ works. You have a Home column, which is strictly things the people you follow have tweeted and retweeted, in chronological order; and you have a separate Activity column for those other things (and optionally more columns for searches, lists etc.)
There's tweetdeck.twitter.com, which is in chronological order, and gives you separate Home (posts by people you follow) vs Activity (other things related to people you follow) columns, as well as other configurable columns for notifications, searches etc.
Parties in Virtual Worlds are great in this regard, since you can see not only someone's name but also their IM address, profile and sometimes notes you've made about them in the past. So I know I'd appreciate it in RL.