As far as I know, Symbol font names will be displayed using a system font in Word’s font list, while non symbol fonts will be displayed in the font’s typeface. See the FontCreator manual on changing Unicode fonts to Symbol fonts.
The size of the font is determined by Word or perhaps by Windows Appearance settings. It is not embedded in the font itself. However, some fonts look bigger than others at the same point size. This is true on the page as well as in Font drop-down lists. To maximise the size of a font at a given point size, recalculate the font metrics — Format, Settings, Metrics, Maximum, Calculate. If glyphs overlap the Win Ascent or Win Descent they will be clipped in most applications. If they fall some way short, they will appear smaller than other fonts at the same point size. See this forum’s FAQ for some explanation of font metrics.