7 secs is real bad, should be out within a second.
The noisy tappets can be down to low mileage if new ?, some do take a few miles to fully quieten, some of mine took 50 miles till totally happy, and ones buggered up now!
The most likely cause is the oil filter allowing drain back, this has/should have a spring loaded disc inside which keeps the system full of oil after shut down, so could be a simple filter change to sort, I recommend MAHLE, I won't use a ford one, too much rust inside for my liking, had a few ford ones leak from inside out due to rust as well.
tabetha