My ~ key is at shift+^, ^ is two keys right of the 1-9 row, so it's really hard to type. See
https://en.wikipedia.org/wiki/Japanese_language_and_computers for more information about that layout.
Would be really awesome if hero was on 4... I guess the only reason you didn't put it there in the first place is that you plan on adding more spells in the future.
Making the keys configurable instead would be a big help, otherwise you'll soon run into the questionable pleasure of coming up with a single config that works for AZERTY, QWERTY, QWERTZ, Dvorak, etc.
Not
that big of an issue, right now I mostly ignore the hero apart from initial placement, reinforcements are way easier to summon. Just would be nice to be able to play more efficiently.