Red Lines from Face Lift Sutures

What you describe is a fairly normal occurrence following facelift surgery. At 7-8 weeks there is a moderate amount of wound healing ongoing. In fact, there is quite a bit of collagen remodeling taking place along the incision lines. What you see in terms of a fine red line represents to some degree preferential blood flow to these areas as they continue to heal. As long as the redness remains confined to a fine line you will see progressive improvement with time.

If, however, the fine line turns into a wider scar with more redness and hardening, you should consult your surgeon. This might be indicative of hypertrophic or keloid scarring where too much collagen is laid down by your body during the attempted healing process. This can usually be managed with a series of steroid injections.

The body heals incisions by increasing blood supply to the area.This brings oxygen nutrients and all the cells active in healing the surgical site. Generally speaking the incision itself may remain red for a few months until the process is resolved. Complete healing and remodeling continue up to 1 year. You are still in a very early stage of healing.
When you mention red lines developing from the suture area behind the ear a few things come to mind. Sutures are considered foreign bodies and the body will have a reaction to them. The reaction to absorbable sutures is more dramatic and can cause localized inflammation. Tension across a healing wound may also appear this way as a scar widens to minimize the tension across it. Localized infection in the suture line may also present this way.
I would recommend returning to your surgeon for a follow up and express your concerns. There are things that can be done to improve the appearance of scars in the early post operative period. If this is just the normal increase in blood supply to the area after surgery all that is needed is your surgeons reassurance.