Mechanically, I see only two problems; your items should be at base power 6 (5 lore +1 specialization), and at base frequency of 3 (1 base +1 specialization +1 focus). So far, all your enchanted items are at about half the strength they should have. The correct writeup would be;
Rams Head Ring: Spirit Weapon: 6 Attack; 3/uses per session
Onyx Stud: Spirit Block: 3 vs. Perception, Duration 3 rounds; 3/uses per session
Ruby Ring: Fire Weapon: 6 Attack; 3/uses per session
Cobalt Ring: Spirit Block: 6 or Armor: 3; 3/uses per session
The second problem is that foci for evocation have to be either offense or defense. So that focus for +1 Earth control either costs 2 slots (to give both offensive and defensive control) or only gives one type of bonus; offensive or defensive.
Build-wise, you currently have a +1 power for Spirit without the corresponding control. Not only you are going to miss more often and thus your Spirit spells will be less effective than your Earth spells but you won't be able to actually use the extra power without taking physical stress. I suggest you eschew a spirit power bonus. Put it into control bonus instead OR put it into boosting your Earth control to +2 OR put it into getting 2 potion slots. What artificer has no potion slots?
In addition, you could put most of your focus bonuses into specialization; you could have Power +1 Earth, +1 Spirit, Control +1 Earth (fixing the focus problem) and Crafting Complexity +1, Frequency +2 (shifting your other focus to a specialization so it cannot be taken away)
Suggestion:
Potions have the drawback that cannot be recharged - they have to be brewed again. However, they do benefit from tagging/invoking aspects and declarations. With your resources, you could "buy an obscure recipe", "buy quality ingredients" and "buy quality alchemy instruments" for your potions (in effect, applying aspects via the resources skill), ensuring that your potions will be at the maximum strength of 10 for your Lore.
And remember, your potions still have 3 uses / session, even if you cannot recharge them AND they can contain almost any evocation or thaumaturgy effect. So get at leadt 2 potion slots.