Awning fixed to existing brick ret...

If I were you, I'd use the threaded rod imbedded about 100mm in the wall. Make sure you have at least 5 threads showing after you tighten down the nut on the threaded rod. That will help you decide on the length of the rod. Make sure you use epoxy to hold the threaded rod in place and everything will be fine. However, if a big enough wind comes by, the awning may come loose from your house. Have you thought about a retractable awning? It will roll up next to your house. You only have to unroll it and connect the legs in prepositioned holders. During a storm, you probably won't be outside anyways, better to have the awning rolled up for safety.