Since you mention scrolling using key repeat - it truly is painful to watch someone do it on default settings. And there are usually better ways to do that sort of thing. But sometimes, there is no substitute: going to the right spot in the middle of a word/line, moving around a page, browser title bars, etc. Here's the kicker though: most keyboard repeat rate settings around have a maximum that is pretty much unusable! But you can fix it thusly:

xset r rate 180 60

When I work on my computer it's like driving a Porsche. When I sit at someone else's it's like I tripped over a door threshold.

There are ways to adjust this on OSX too but it's a lot more touchy. Haven't attempted on Windows.