Purina isn't a bad food, I don't personally feed it but a lot of the breeders/show people do on here and I think a lot of people have had good success with it.
I pretty much agree with everything everyone has said. I also really agree with the alfalfa hay, you don't really need to feed it. If you do decide to and your breeder hasn't been feeding it, you have to start them out on alfalfa really slowly because a lot of times it causes stomach upset. I gave my baby bun alfalfa for about 2 weeks, along with her grass hay and I only gave her two small handfuls a day of it. I wasn't feeding an alfalfa based food though, then I switched to an alfalfa based food and stopped feeding alfalfa hay. Plus people say when they babies eat alfalfa, its hard to transition them over to grass hay when they're old enough.
I also only fed my baby bun(who is a dutch, so different than a holland) about 1/2 cup a day, split into two feedings, morning and night. It caused her to eat more hay during the day, which is so important. Because as Kipcha said, too many pellets=less hay eaten.
Once my baby bun got a little older, I added two more varieties of grass hay to her diet, to change up the texture and let her kind of choose what she wanted to eat. So now she eats mostly coastal, with handfuls of oat and timothy everyday(they're like her treat hays because they're expensive oxbow)
Molasses is in most rabbit feeds. The only ones that I don't think have molasses is Sherwood Forest and Oxbow Beneterra Organic(and that one I'm not sure, I just sort of remember it not having molasses, someone correct me if I'm wrong) I think they use the molasses as a binder or something, but thats the reason most rabbits LOVE pellets is because rabbits have this massive sweet tooth! haha. Thats why you measure your pellets and limit them, to encourage more hay eating and then once its old enough to eat greens, you encourage green/herb eating. But no greens until its 12 weeks or older.
You mostly want to stay away from foods that have the colorful bits and the "treats" in the feeds. Like anything that says "fiesta" on the bag, is probably going to be a bad choice for the pellets. You want to stay away from whole corn kernels, I would assume that some feeds have corn in them, but they're mashed up into the pellet, not the actual whole corn kernel. They can't pass the skin of the kernel.
Hope that helps! And when you get the new baby, post pictures! We love baby bunny pictures!