Thanks guys for the information. I think I am heading into the right direction. This will improve things a lot :).
And zombies are not scary anymore. They are overused and if someone wants to make a new type of zombie, then it needs to have a different feature set. It must be reinvented, because the old zombie idea is dead.
Regarding the blueprint: I am creating a ghost blueprint, which can teleport in any rooms. It just needs the constructed blueprint waypoint node, so it can spawn in the according room. The AI will be pretty advanced, because it will be able to toy with you or hurt you. It behaves differently each time and it will have a lot of options to interact with the environment.
When I think about it, it looks like a newbies plan with a lot of ideas^^. Trust me, I am no amateur in blueprint scripting xD.