I would use the 'protection' products in the daytime and keep the 'nourishing/treatment' products for night time. Aromessence Excellence is for regenerating the skin so would use it at night. I know Decleor recommend you using that in the mornings but I've always used them at night as I think they assume you will be using their night balms. If I wasn't going out in the day at all (no need to use sunscreen) then I would use the aromessence in the morning followed by day cream.
When using Ultrasun you really shouldn't create any barriers between it and the skin.
Sorry if I'm I coming across all informative but I've been a therapist for 12 years and sometimes have to stop myself getting carried away writing essays on skincare! :blush: