I think your routine looks quite good overall - have you noticed a positive difference since starting it?
In terms of improvements, I'd suggest going for a higher SPF for under the eyes (maybe even using your face day cream in this area if you like the cream?).I would also not use this eye cream at night because it contains SPF (and you don't need it when sleeping - and it's better to avoid unnecessary ingredients in skincare whenever possible).
And a question re the 2 retinol products in your PM steps: Skinceuticals and Elizabeth Arden Capsules: do you use them on alternative days, or both daily?
Just got your response in the email! Yes, good, just one retinol product at a time is enough, and both products in your routine are a good choice!
For reducing the number of products you use, removing the eye cream (and using the face moisturizer instead) won't take away from the results.
You could also choose a different moisturizer with sun protection - something with a good percentage of niacinamide (it's the active ingredient in the Skinceuticals Discoloration Defense Serum), so that you don't need to repurchase the serum once you run out. Here are a few options for good sunscreens with niacinamide:
Also, when your current night cream runs out, you could try something else with a bit more "punch" in terms of helpful actives (including niacinamide, which is more effective when used 2x per day). For example: