Hey Im new too, but I think I can help. Many times muscle twitches are a sign that the muscles are releasing tension and relaxing, so id just ignore those. As for the light it could be your entering the dream world, or just a hypnagogic hallucination maybe. Next time it happens open your eyes(if they arent already) and just look around. Honestly WILD is one of the hardest techniques for a beginner many have said, also the most tiring. Personally I would suggest you attempt DILD, its far more easier and you dont lose any sleep trying it. Oh yeah by the way whenever you feel an urge to move your body Ive heard from many people its your body sending signals to move to your mind to see if your awake and if you dont react to them you body falls asleep faster.