I have made several batches of hard lemonade over the past few years and I use a yeast starter or a slurry from another batch of wine. No acid blend is needed as the lemonade is already acidic enough. Nutrients are a good thing.
You may want to acclimate your yeast to the lemonade a little at a time until it is working nicely, then pitch it into your primary. Add maybe 1/2 cup to your starter every few hours and let it work.
I don't carbonate my lemonade, but do add some sprite or soda water to the drink is someone wants it fizzy. Another alternative is to force carbonate the beverage then bottle it.
I also add 375ml of Lemoncello to my hard lemonade to kick it up a bit. We make the Lemoncello from Everclear so it's quite potent and flavorful.
I am at work and do not have my notes, but we make 3 gallon batches and I use 8 cans of minute maid lemonade and sugar (Simple Syrup if possible) to an S.G. of 1.075. You can sweeten or adjust your flavor by adding more lemonade mix later, but I have never had to do so. I have added a simple syrup made with fresh lemons as a sweetener and it works nicely.