i cant speak for those other car makers but Nissan can over engineer their cars sometimes..
yes if the BCM detect a high ambient temp range in the engine room prior to start, it will send a pulse to the clutch fan to turn on. this can happen randomly and will happen more and more if you drive in warmer weather. you can leave the car in the sun for a few hours, raising the engine room temp, and once you turn the car on it will roooaarrrrr...
just this morning at 430am my time i got in the car and this started up. the day prior it was a little warm here in LA (mid 70s) and i was driving, ahem, spiritedly..
got home (garage kept) and dint get in it until this morn.
point is this is normal. you may not hear it again for several weeks and then you will hear it once or twice. also when you are in stop and go traffic and/or running the AC and you are idling, expect to hear the RROOOAAARRRR kick on when you accelerate. come back and say "marc you were right" whenever it decided to get warmer than 12 degrees!
also, when you first drive, you should hear/maybe feel the brake ABS making a little ticking sound for a second.. perfectly normal.
that ticking though in the hood??? that is not good brotha. go to a different infiniti dealer and have them listen to it/watch the video.
ive actually heard a similar sound from another qx driver who posted the same type of sound. i think its the valve lifters/something inside the engine related. again ive n ever heard that on the 2012 i drive and the engine is the same.
yes please find out of it varies with acceleration!