I definitely
agree that there should be more Talents which change playstyles. Right now the selection is not great.
I think Far Out Man is fine as it is. Your suggestion for Battlemage is questionable because there are so few low-range spells that it would be more of a disadvantage than an advantage.
Your revised Far Out Man is okay, I guess, although I'd only approve the change if a bunch of other Mage-specific Talents were added. Right now the selection is so low that Far Out Man is one of only 3 Good Talents for mages. I would not like it if Larian changed Far Out Man to your idea WITHOUT adding in many more new mage-specific Talents.
Avatar is I guess okay, although I don't think it's reasonable to specialize in four elements, that's a lot of ability points. Having to cast spells in a specific element order would be pretty restrictive as well, and that's not much of a benefit in exchange.
Good suggestions, especially for Demon and Ice King.