The beauty of Reaper is that you can customize your keyboard in whatever way you want. Some like toolbars, others like shortcuts. I'm in the latter group, and if there were a Reaper keyboard, or if I did the stickers thing, I would abandon them right away because I am always changing my shortcuts either way. Four years using Reaper and I keep discovering new ways of doing the same old things. I am always looking for ways to improve my workflow especially when it comes to editing, because the faster I edit, the sooner I get to mixing. I hate editing by nature, but ever since I switched to Reaper (from PT) I am more and more enjoying the task. So every week or every couple of weeks I come across a new way of executing commands, something easier, something faster.
Since I am not answering your question, let me introduce you to the most radical and immediate solution I have found in Reaper when it comes to shortcuts/toolbars (this is actually sort of a marriage of both): The Reaper Radial Menu.
https://www.youtube.com/watch?v=Zs1qkpF8_tE
You can start using it as is and, as I do, change things here and there as time goes by. I always wanted to have soooo many shortcuts and combinations of commands and such, I started running out of keys to assign them to, and was always going back and forth with my right hand between keys and mouse. Now 99% of my commands are done with my left hand on the keyboard (fingers on ASDF, thumb on spacebar) and my right hand on the mouse, and I don't even need to get my eyes off the screen, rendering the backlight function on my keyboard useless. I have assigned it to the letter Q, it's what makes the most sense to me. Try it out, I can't recommend it enough!