Sounds about right for the feed. I've not come across the DN line before but that still sounds a little low to me for cal-mag. Most coco users will be looking at about 2ml per litre.
PPMs sound about right and the plants look good to me. Looks like you'll be fine from now on.
No, you shouldn't be feeding full strength. Autos usually don't like it and the addition of the soil will be providing some nutrition anyway. 50-70% would probably suffice, but the plants will be quick to let you know.
AN is very expensive and you won't see much love for them around here. There are much cheaper out there that do just as good, if not better. Lots of people are into Mega Crop, I've not used it but seen great results and it's very affordable. General Hydro are pretty good too but require some additions at flower.
Your plants are looking great, I wouldnt lose too much sleep over it, you'll be fine, keep it up!