To answer your question to the best of my ability....no, you do not need an internship after you pass boards. You may start at the first place who will hire you. I think the internship is a relatively new concept and is not in place at all places, or even most places I think. The one you are talking about sounds very complete.
I don't know if most people need an internship or not. I graduated in 1973 and we were allowed to work as student nurses during our last year of school and until we passed boards. We did team leading back then and learned great organizational skills, people skills, meds, procedures etc. In all honesty, we had very little supervision, and didn't have any idea how dangerous we were.
The idea of an internship is to give you time to get your skills down pat before you are on your own. Some people need it, some not. If you have had no healthcare experience or if you are very young, I think it might be a good idea. But if you have life experiences, have been a medic, tech, etc and already understand the lingo, flow of things and how to interact with people, then maybe you do not.
I don't think a 2 year committment is too much to ask, because they are spending a lot of money on your education. In the beginning, you will not even be counted as staff even though you are working. You will be with a preceptor who you will shadow a while and then gradually begin to take a heavier and heavier patient load, while still having close resources.
It is a toss up as to weather you need one or not, but it is not required in most places. Good luck on your adventure.