Are products with ceramides, hyaluronic acid, cholesterol and niacinamide generally helpful for oily, sensitive facial skin dx seborrheic dermatitis?

No: These are very useful for DRY skin and eczema. Seborrheic dermatitis will respond to an azole cream such as ketoconazole, clotrimazole, or miconazole. Topical steroids are very effective but on the face calcineurin inhibitors are preferred. Washing with a dandruff shampoo, typically in a shower, can be very beneficial. Some meds and vitamins aggravate it.