I don't think a manasteel to elementium upgrade recipe would work very well here, unless you use elementium to make terreasteel armor (either as base recipe or alternative recipe), because there's little incentive to use the pink armor over the blue one (not typing manasteel and elementium every time I'm too lazy) besides the pixies, and even then, would it be worth the double materials (double as in, you would need 2 sets of blue, one for pink and one for terra).. I dunno
IMO we could have a boost here for pink armor, be diamond level, maybe increase the discount to 20%. (I was convinced terrasteel was 35% discount but is 20% so nevermind)
for the pixies.. well first make them fast because they're quite useless rn (literally snails), they do block projectiles if they hit them so that's a little good thing about them, maybe you could also have them orbit the player if they survived and there's no more enemies around (max of 3 or 5)
For the tools... they're kinda weird.. the shears... I don't think I have ever seen anyone use the special effect of them, specially when you have a drum that does the same for free.. but I don't know what could it do instead (maybe the range shear could be like the horn of the wild but with silk touch?)
The hoe, dunno the use of the hydrated farmland, but the best I can think is aoe farmland so I guess it's good enough
Pickaxe I think is good as it is, it gives an actual different use for the tool, I would love if you could add blocks to the list it destroys (in game not thru datapack)
Shovel is ok I guess, maybe make it a little faster? since we don't have a terra shovel
the axe is literally the best think in botania don't @ me
and for the sword.. well.. I dunno, like, really dunno.. I can think a lot of stuff that doesn't really work on minecraft so I guess it's good as it is with a little bump?
EDIT: wait I forgot, for the shears, alternatively, could make the secondary effect drop string instead of wool (with a better conversion than the mana recipe)