If you are going to the trouble to take the pan off, I would change the screen. The screen looks like a pain to clean and it is cheap.
The fluid is a whole 'nother story. If the label says it, I'm good using it. I know some people are "dealer only", but Nissan doesn't make oil or transmission fluid or gear oil or batteries or spark plugs or lots of other pieces/parts that go into a vehicle. Same for any other vehicle maker. I have a VW Touareg and a poster on a Touareg board says if you can't afford OEM and dealer service then don't buy/own a "$60,000 luxury German SUV". I routinely poke the bear with him when I show off my Amazon or ebay purchase for it. Good Lort!