Engine "tapping" noise 07 RL

I just got a 2007 Acura RL(first Honda product) with 145K miles, well maintained one owner car. I noticed a "tapping" sort of noise while engine is idling and while driving from 1k to 2k rpm. I was wondering if it's normal sound for a J35A8 V6 or I may have a problem?

Another "concern" I found was after 2,000 miles after oil change with synthetic oil I notice the oil got really brown and dirty, is that normal?

I also noticed that some of the climate control panel bulbs are out, would anybody have information on how to change these bulbs would be greatly appreciated?

Thanks in advance