It would be nice to have Unicode mathematical symbols such as ∀, ∃, ∄ etc in the font. I am willing to draw them myself if there is a tutorial on how to do that.
Which ones exactly? There are 19 of them (from IBM-437 and user requests), but the full set is about 295, many will be tricky to write (2204, 2209, 221B, 221C, 2272, ...), and many impossible (222D, 222F, 2230, 2278, 2279, ...).
Half a Page
Should all sizes of the font include all symbols?
All sizes, normal and bold. For characters with 3 vertical lines, 8x1 bold also includes versions with 1 and 2 pixel middle vertical line - see 'm' or 0448. I studied years ago, but can't remember seeing most of the unicode characters...
I still don't know which characters exactly you need. If you write them, feel free to post a .diff (against the .bdf files included in 4.38) in the patches tracker.