If I were you I'd leave it in secondary for longer. 3 days might be enough to take some of the sediment out but it's not really enough for you to get much in the way of flavor development.
Since your OG is 1.000 even it will probably be a pretty dry cider. Once it's been in secondary a couple weeks, taste it; you will probably figure out pretty fast whether you like dry cider or not. If you want to backsweeten you will need some way of keeping the yeast from eating your added sweetener; there a few ways you can do this.
First, you could pasteurize the cider. There's a pretty easy guide to stovetop pasteurization on these forums somewhere - you should be able to find it with the search function. Essentially, by heating your cider, you kill the yeast and thus prevent them from eating any new sugars. The downside is that this can affect flavor, and can lead to messes and broken bottles if you aren't careful.
Your second option is to use stabilizing chemicals like potassium sorbate. When added to the cider after fermentation is finished, this will prevent fermentation from restarting even when new sugar is added. I don't personally do this because I prefer to avoid chemical additives and additional processing in general, but it's a common practice among many mead and cider makers.
Lastly, you could always just backsweeten with a non-fermentable sweetener, like Splenda.