Having to use the mouse frustrates me. Have you tried an ergonomic keyboard?
I use a tenkeyless keyboard, which doesn’t have the calculator block at the right. The ones which have it I find put the mouse too far off to my right. It’s very important to me that there are OPTION and COMMAND keys on both sides of the keyboard, so that the opposite hand is doing the shifting; I’m never pressing two keys at once with fingers from the same hand. I’ve never used an ergonomic keyboard.
This is a Japanese keyboard with German switches. I’ve had it for quite a while. The Cherry patents have now expired so there are now several third parties making copies of the switches, and many makers of much cheaper mechanical keyboards. However, most of those I’ve seen lack OPTION and COMMAND on both sides. The Filco has OPTION, COMMAND and CTRL on both sides (and, of course, SHIFT).
On that last point, I worded my earlier post wrongly. What I should have said was that you never had to press a key and its shifts with the same hand if the shifts are available on the other side.