#1) Welcome
#2) With quality of fuel these days & seasonal temp changes - consider running injector cleaner through it. (I've been preaching this alot lately but it's common during season changes & temp swings. And as sensitive as our rides are we notice it more than "average Joe" in his American "land yacht"
#3) Vanos are notorious for clatter on cold starts, and as "perf" said it's the oil getting up there that quiets it down. No worries unless it does it more often than at a cold start
#4) Rattling near walls - could be harmonics making exhaust hangar or other sheilds rattle and it's more evident from outside the car or with windows down. (gas tank sheild, brake dust sheilds/backing plates)
Lastly, don't ever feel stupid asking a question here. (As long as it's not where you left your keys or socks) The guys & babes here are pretty damn sharp and they won't steer you wrong.