1.052 sounds pretty reasonable for a cider. Your final ABV will depend to a certain extent on how dry it ferments (which will in turn depend on what yeast you use) but you should end up with something in the normal range.
A darker color after adding brown sugar isn't surprising - after all, the brown sugar is, you know, brown. The color might change a little after fermentation is done, especially since the cloudiness caused by yeast in suspension can affect color during the primary fermentation, but ultimately the color is pretty much a purely cosmetic aspect, so I wouldn't worry too much about it. Ciders with added sugar do generally take a little longer to age, though, so I'd keep that in mind.
As for racking, 1.02 seems a bit high. Generally you're not going to want to rack off into a secondary vessel unless the primary fermentation (that is, the actual alcohol creation) is pretty much done. The only way to tell for sure that fermentation is complete is to make sure that the gravity isn't falling any more, but generally for Nottingham I would expect it to get down to more like 1.01 before it wrapped up. I know you're probably eager to progress (especially if this is your first brewing project) but patience is key.