The primary fermentation for cider is going for 9 days and SG wend down from 1.052 to 1.005.
- Is it normal to have such a low value before first racking?
- Should I add sugar to rise SG to 1.015 and rack it?
It is not uncommon to have SG fall that far after about 9 days.
Adding extra sugar at any point, at beginning, end, or at this point in between, is a matter of preference. Be aware that the added sugar will continue to ferment to dryness and will simply increase the alcohol, unless you pasteurize or otherwise treat to kill off the yeast early. In my opinion, I do not recommend any sugar be added to any cider unless you want it to be more like a stronger apple wine. That is up to your personal preference.
You can rack at any point, just be careful not to over expose your cider to air, to avoid oxidation. There are tips (mostly for wine, but still) for that here: Oxidation of red wine during racking and bottling
Personnaly, for my ciders and my wines, I prefer to rack the first time just before the end of fermentation. The main reason is that fermentation will continue in the secondary and form a protective layer of CO2 on the surface. 1.015 is about right, but there is still enough CO2 in the cider, even when fermentation is completed, it is release to the surface slowly.
So you do not have to add sugar, unless you really want to.