You'll never get > 8 Meg from that line. Max sync is about 7.5 Meg so you are running a bit below par. Otherwise stats are good.
NM should not fluctuate that much. Can you get the stats from the hidden test socket, behind the faceplate and, I think, the other removable bit? Any phone extension sockets?
1999: Freeserve 48K Dial-Up => 2005: Wanadoo 1 Meg BB => 2007: Orange 2 Meg BB => 2008: Orange 8 Meg LLU => 2010: Orange 16 Meg LLU => 2011: Orange 20 Meg WBC