Yes, playing those tunes in B minor on your F whistle would certainly work for both. Glasgow Reel falls nicely under the fingers. And Screw the Nut is mostly in the 2nd octave, so volume might not be a problem even on your low F whistle.
Another possibility is to play them in E minor on a C whistle, which might give you a bit more volume. For Screw the Nut you’d have to make a few adjustments and octave folds, but it works pretty well. For Glasgow Reel, it works best if you transpose the A part up an octave, along with the last 2 bars of the B part.
There’s no real getting around the additional chromatic accidentals in Screw the Nut, with its harmonic minor scales. But they’re not so many and not necessarily so hard. In B minor, in addition to the normal F# and C# of the key, you also need A# and F-nat. In E minor, in addition to the normal F# of the key, you also need D# and A#. In almost all these cases, half-holing works well because of where the chromatics occur in the melody.
If it would help for you to see any of these tune/key combinations written down, I could do that for you. Let me know, and good luck!
If The Glasgow is Tam Lin, I play it on a low G whistle. I’m playing it as if it’s in the key of A minor, but it comes out in D minor:
xxx xxo
xxo ooo (x3)(long roll)
xxx xxo
xxo ooo
oxx ooo
xxo ooo
xxx xho (x2)(h=halfhole)
xxo xho
xxx xho
oxx xho
xxx xho
xxo xho
xxx xho
xxx ooo (x2) (short roll)
xoo ooo
xxx ooo
xxx xxx
xxx ooo
xoo ooo
xxx ooo
etc
It sounds cool to partially open the F hole for F natural (actually B flat) and do the “rocking” thing.
You only need to halfhole if you want to play in tune with other instruments and they’re in another key, one person shall have to transpose or it’ll sound bad. If you play by yourself the fingering is the same, whichever key whistle you use