I have done a few batches of Ed's Apfel wine and want to try something a little different maybe a little sweeter.
I would start with the 5 gallons of apple juice.
32oz of Blessed Cherry cherry juice concentrate
Wyeast 3068
I haven't decided on wether or not to add the 2 lbs. sugar yet and
Do I have to worry about the acidity that the cherry concentrate will add??
Using a beer yeast is the way to go if you want something which will finish sweeter. Now that cherry juice is gonna give you an issue with extreme tart flavor and the 3068 might clash with it.
Here's what I would reccomend. We need to control the tart and sour which will happen from adding the acidic cherry juice. I reccomend steeping .5 lbs of crystal 60L in 2 quarts water at 155 degrees for 30 mins. These crystal grains will offer some balance and some sweetness.
I would also use a clean fermenting ale yeast and not 3068. Wyeast 3068 is a great yeast but if you want the cherry to come through then you want a clean fermenting yeast, 3068 has a very specific taste profile which will be pronounced. It may taste good, it may not....I don't know. But I do know using 3068 will give it a distinct 3068 flavor along with the cherry juice flavor.
If you use a clean fermenting yeast like safale s-04 or safale s-05 or nottingham then the cherry will be the main flavor.
As for the sugar, I wouldn't add it. If you must add sugar then add 1 lb of brown sugar. If you want to retain some sweetness from a sugar source regular dextrose wont do it. dextrose will ferment out completely.
If you really want to up the ABV and leave some residual sweetness and maybe a pinch of Body, use some light DME (Dry Malt Extract). This will add another layer of complexity to your cider while upping the ABV and ensuring some residual sweetness behind.
What you will end up with, is something that is definately not a dry cider and definately not a sweet cider. Brew it, bottle 3 weeks and then try it. The cherry will be there, slightly tart and a hint of sour which readily gives way to a slightly malty finish. It will get better with age, but will be good after 3 weeks in the bottle.
PS. if you really want the cherry flavor to come through you will want to use a gallon of cherry juice. But the 32 oz you listed will still be good.