SDL Tridion 2013 fixes Schema navigation by letter presses. Navigating by the tab key seems to work for me as well, though I had issues with IE in compatibility mode.
2013 also adds a useful "clear field" option with an "x" in the right side. If possible, I'd have the authors test run 2013 to see the improvements.
I also noticed a "tall fields" issue in 2011, follow-up with Support on that one if it's an issue for the authors.
