First, I have Ctrl+Shift+U set to Underline. But something I'm doing
seems to add more and more Underline symbols to the Macro toolbar, and
I can't seem to get rid of them.

Second, I have Ctrl+Shift+D set to Symbol - Alt+0186 - Times New
Roman, but occasionally it switches to MS Mincho instead of Symbol for
no apparent reason! This seems to happen only after a certain point in
the document, and I have to delete the section and type everything over
again.

Any advice?