Definitely secure the tree. We screwed a little eyebolt into the wall and after the tree is up, wrap fishing line around it and tie it off. That way if it goes "timber", it won't fall all the way over. Most of our ornaments aren't glass so that's not a problem and we don't use tinsel. But, might want to check the tree if your cat is missing. We once came home and found Cudsey Marie hanging upside down in it. She had somehow gotten the lights wrapped around a hind leg. Kitties have never eaten the hooks but I liked the posted idea of tightening them around the branches just in case. I'd suggest string or ribbon instead of hooks -- but that would just be more of an attraction to the kitties. Also, I'd stay away from blinking lights. Kuhio never attacked the tree unless we put blinking lights on it.

Also, we usually have a "real" tree. Our kitties never liked the smell of the sap so they tended to stay away.