Ok here comes an open ended list

not everything is a
must doSpecilisations: i would choose spellcasting instead of counterspelling and conjuring instead of banishing.
Reason: Counterspelling is rarely used, spellcasting is used all the time. You can use summoned spirits to battle other spirits instead of banishing, and banishing is twice as draining as summoning.
Qualities:-I would consider getting "Focused Concentration" at least Rank I for one free spell sustain. Especially since you have picked 2 sustained spells.
-Analytic Mind is so good and cheap any hermetic mage needs it ^^ but i understand if you dont want it for balancing reasons.
Powerpoints- with sustained spells you cant walk trough "Mana Barriers" meaning when your GM secures any mid location with a Mana Barrier you walk right into it and cant even see it ... with the Charisma 1 its almost impossible to "sneak" trough it except when you use "Increase Attributes" Spells beforehand ...
So I would pick "Astral Perception" and default on Astral Skill.
PrioritiesSwitch Metatype D and Magic C. You gain points by doing so. Put the extra points in Edge. Edge 1 is terribly low. With 5 Edge you can summon a strong spirit easily (use Edge to force its hits to reroll)