>>646
Hemomancy: both offense and defense
Ruins: The rest can arguably be earned given effort and time, but secret skills can't.
>>656
you'll need develoment on what each craft does and what are it's limits. For exemple, do humans count as animals for Terramancy? can you transform into a Lich with Necromancy ? What exactly can you summon and how do you get them to help you ?
Can you create your own magic items relative to your craft or can you only get some from the Tower ?
Same for the Areas. Does Archives make you cap out at a higher level ? What is the spellcasting increase of the crystal caves. What gear do you find in the Tower ? ect…
Perks (metamagic?) and Drawbacks (sicky?) are a classic for a reason too.