fumbling with a seek bar or positioning my mouse just so and thumb-wheeling.
If you are in Standard View, or any view where you are using a mouse, hovering over the play/seek bar would be just as easy, if not easier, than aiming at and hitting an on-screen button.
I have assumed that you meant on-screen buttons rather than keys, since you said button in the original post.
In regards to FF/REW, <snip> Microsoft MCE remote FF and REW buttons will go ahead and back a few seconds (only a small fraction of what is specified in Audio->Jump Behavior).
The FF and REW buttons on a remote or on-screen are completely different things to the LEFT and RIGHT buttons on the remote. Therefore, it isn't surprising that they do completely different things.
But using my VRC-1100 remote (that issues Keyboard format codes) the FF and REW don't do anything at all in Standard View (even though all the other buttons work fine - Pause, Play, Stop, Skip, Skip back).
The FF and REW buttons, on the remote and on-screen, do something for me in all views, for audio and video. Different things in different places. This seems to an issue with your remote, not MC.
In full screen video, right and left arrow will go forward and backward the amounts specified in (logically) Tools->Options->Video->Jump Behavior.
Also in windowed video, whether detached or not.
Anyway, I would not like to see screen real estate taken up by more buttons, especially next to the seek bar.
The solution to the issues that both of you have
may be in defining Global Shortcut keys for MC to use. Keys that would work in all views, including Mini, Standard, and Theatre Views. They require a bit more effort to set up (and I'll admit that I haven't set any up, having only played a bit with the functionality), but you can define your own keys. Just make sure that the key combination isn't already being used by MC (look through the Resource.xml files) or Windows. You would have to work out which command too use; maybe 28004 and 28005? Give it a try.
Kstuart, you can then program your VRC-1100 remote to send the correct keyboard commands to MC.
Jaxtherogue, would a keyboard shortcut rather than a mouse click work for you?