Answer:
I weaken all men for hours each day. I show you strange visions while you are away. I take you by night, by day take you back. None suffer to have me, but do from my lack.
Add a T and I shoot through the sky. Then add an S and I multiply. What word is it?
Always wax, yet always wane: I melt, succumbed to the flame. Lighting darkness, with fate unblest, I soon devolve to shapeless mess.
Two in a whole and four in a pair. And six in a trio you see. And eight's a quartet but what you must get. Is the name that fits just one of me?
What holds names and memories which are not its own?
Those with eyes bigger than their stomach will definitely leave the restaurant with one of them. It is named after a house pet as well.