Hello Tso91 and welcome to Thunder’s Place! :D
1. The Newbie Routine is an excellent routine to start with. It conditions your penis, and gives you gains. You can keep following it for as long as it is working, for many months to come.
In my opinion, the MoS routine is very intense. Especially for a beginner.
Stay safe, and gradually workout your penis, to encourage growth, one step at a time. PE is a long term process, it takes patience, persistence and consistency, but the results are out of this world!
Please read the following threads, and learn as much as you can about the exercises before you start practicing.
Physiologic Indicators (PIs) to help growth!
Jelqing & Stretching 101
Warning! If you haven’t gotten improved erections
Quickstart guide
2. A 5.5" long penis is average, gains of an inch are more common than two but some do gain two inches or even more, it is not impossible, however, it will take a very long time.
3. After you have reached your goals, you should follow a maintenance routine which is a lighter version of your regular routine, until you cement your gains. If you quit long turkey, without making your gains permanent, you are likely going to loose them after a while. But even then, they will come back quickly if you resume PE once more. That being said, after you notice the positive health benefits of PE, you will get addicted and never want to stop. :D
4. You do not really have to change your routine after a certain period of time.Usually, it takes two to three months to condition your penis. After that, if you are still gaining from the newbie routine, keep following it, until the gains stop. After that, you gradually increase the intensity of your routine, or do an intermediate exercise.