About the tier thing: one RN program that I am aware of does exactly that... While in their program, you first earn the CNA (pretty quickly, actually), then you earn the LVN, and then you go for the RN. Along the way and where appropriate, you do take the appropriate certifying and licensing exams. The program does take more time, but then again, the idea is to get you working so you get paid experience along the way while you learn. You do go to your clinicals separately, so those are still unpaid learning experiences. At the end of their program, you can say that you've been an LVN for the past year or so, working, and now you're a new grad RN. You may be a new grad, but you at least you're not completely inexperienced.
And yes, it's an ADN program.