Retinols should be used in the evening. Wash your face then apply the retinol. If you wish to apply other products on top you may, it is just recommended that you wait for several minutes after application. You can use the Serum CF just in the morning and the retinol at night to make your products last longer.

Since this product doesn't state that it can be used around the eye area, it would not be recommended. MD Forte makes an eye product that contains retinol.

Yes, there shouldn't be any contraindications against using the two products together.

Yes, it is on the liquidy side which helps it spread easily and cover "more ground' so to speak using less of it.

I use this AS a moisturizer at night because of the ingredients and because it is rich.; but first I use skinceuticals b5 serum as a base after cleansing because it seems to lock in the moisture of any product I use it with and feels delicious on the skin. I suggest you try the Topix serum on your neck first to ensure you don't have sensitivity to it. My skin, which is highly sensitive, responded very well to it. Good luck!