I have fixed the keybindings for the browsers (this has been in git for a time now), and if you press alt, you get a nice overlay with what number to hit. If a number is shown twice, you can switch between the two by hitting the key twice. So to get to the wikipedia lookup, you can get to it by hitting alt-1 when on now playing, so if you are on play-queue, hit alt-1 twice to get to the wikipedia lookup.
I am still looking for some help on GMPC, LibertyZero seems to have vanished leaving me with a 1/2 done sidebar. I am currently working on getting glyr working, this should replace all the input plugins.
But I am looking for somebody to write a nice metadata editor. (glyr frontend)