I can now report on the Verdana issue. I had feared that the hints would not be properly preserved by the font editor, but my fears were groundless. Herewith the font techno-guru's report:
"I cracked the font open in FontLab and made a visual comparison to the
MS Verdana font. The hints appear to be preserved perfectly.
If one only wants to change the vertical metrics and be sure not to touch anything else in
the font, the easiest method is to use Just van Rossum's TTX tool: do a dump of just the
OS/2 (for Windows metrics) and hhea (for Mac metrics) tables, edit the XML files in a text
editor, and then fuse the tables back into the fonts.
That said, my experience of FontCreator is that it is pretty good about not touching table
data unless one intends to edit that data.
Almost all Windows apps (mis)use the WinAscent and WinDescent values in the OS/2 table to
calculate default linespacing, not the Typo values. Maybe NotaBene is different. To obtain
compatible metrics, the OS/2 Win, OS/2 Typo and hhea table metrics all need to be
compatible, i.e. equal the same total height."