Sizable windows
 

I would like to see all the windows be sizable, as the buff and chat windows are. Is this possible? Hopefully this would enable modifications like the big player info bar on the fly, and removable as needed ie: grouped vs soloing.

I love playing at higher resolutions, but frankly my old eyes have trouble seeing some of the smaller UI windows like TARGET or my own health, or even the spell icons and hotkeys.

Font sizes
 

There is a property in the XML to set a the font size of each "widget." You would have to reload with /loadskin each time you changed it, though.

hmmm
 

I had this idea too. Unfortunately it wont work. I have /feedback'd in game and emailed verant. Right now you can only define widget sizes in pixels and locations in pixel offsets from the edges. This means you could make full-width widgets get wider when you resize, or full-height widgets get taller, but you couldnt make them expand in other directions so it would just look very thin and ugly. I asked them to make all sizes and locations specifyable as percentages (like you can in html for table rows/columns) which would make what you are asking possible.