R56 MCS Engine Noise: "Death Rattle" or something else?

I purchased a used 2007 MCS in Aug 2015 with 42,500 miles on it. It currently has 43,500 miles on it. I'm a first time Mini owner.

In Nov 2015, I took it to the local Mini dealership and they replaced a cracked valve cover. I stopped driving it 600 miles after the valve cover replacement because of an engine rattle that made me nervous. I have been reading and watching videos for the past month trying to diagnose this thing, but am having no luck. Since I've owned it, the oil has been at max level. I have also changed the oil and spark plugs. There were no particles, shavings or anything in the used oil after I changed it.

This is a video I took of the noise. The video starts at idle, then is brought to 2K RPMs, then back to idle, then back to 2K RPMs. There are actual two noises that are in question:
1. At idle (22-26 seconds into video) there is a rattle noise. Is that normal? From what I'm reading and watching it sounds like it could be, but I'm not sure.
2. At 2K RPMs (30-38 seconds into video) there is a different rattle noise. This is the one that really bothers me. From what I'm reading and watching, this is the one that sounds more like the "death rattle", but I'm nut sure.

I called the dealership and asked about prior timing chain service that was done on my car. In Nov 2013, they did a service check of the timing chain and timing chain tensioner. Records read as follows:
COMPLAINT: SIM 11 04 13 - Service Action: N14 Engine Check Timing Chain Tensioner and Timing Chain.
CAUSE: The timing chain tensioner internal tolerances are not consistent. 00 61 055
CORRECTION: Checked chain tensioner, tensioner has dimple and requires no additional action.

I asked for an explanation of the CORRECTION comment and they said that it already had the new style and didn't need to be fixed.

Thoughts?

2/16/2015 - I removed my valve cover and the timing chain is tight to the touch and doesn't sag. Don't know if that helps with diagnostic.