The answer to your first question is yes. Both web pages list the same Coolermaster part number.
The answer to your second question is a lot of enthusiasts prefer to use a third party thermal compound. Arctic Silver 5 is still popular; however, enthusiasts all have their own favorites.
The answer to your third question is adding a second cpu heatsink fan for a push pull effect will lower temperature but only a little bit, usually less than one degree. Individual results will vary.
I started using IC Diamond 7 Carat thermal compound several years ago. Results have always been excellent for me. Just have to remember to follow the manufacturer's instructions.
Also if I add a second fan to the heatsink will it take off a few more degrees?
I forgot to answer this question.
Johnny Lucky is right about his answer to this question but getting a better fan than stock does give better performance and since you have the other one than use that one as well. Remember to use the stock fan as your pull.