If you're going for GWAMM in the long run, it's better to just do Master of the North, and finish off the reputation titles you haven't maxed afterwards. Otherwise you will waste a lot of time farming the rep titles you could've done simultaneously with Master of the North (you'll get a full NM and HM hero's handbook and a full NM and HM dungeon guide). The books you'll get alone are worth 150,000 reputation points, not to mention the points you'll get from vanquishing (asura, norn and ebon) and while doing the dungeons (dwarf).
If you just want a few easy and fast titles, there are others that are easier and faster than eotn rep titles. Canthan protector (master reward in all NM missions in factions), lightbringer/sunspear (very easy to farm and reasonably fast, faster than eotn rep titles anyway), for example.
As for the kurzick/luxon problem: you only get double points for buying skills and donating to the alliance. After you buy all the luxon skills on all your chars, you can only get double points by joining a luxon alliance/guild. If you're not willing to do that, you can spend the points on whatever you want (scrolls or jade, whatever you fancy more). You will get 1x the points from any. In any case, trying to get max luxon in a kurzick guild is making it much too difficult for yourself. If you really want to max luxon, you're much better off joining a luxon alliance and donating to them. Why don't you just go for Kurzick since you're in a kurzick guild?
