Is it safe to do the newbie routine more than once a day?
Sure, but the choice is up to you. Here are your possible outcomes.
1) You might make some really awsome quick gains.
2) You might overtrain
3) Either way, you will probably condition your penis very well. And what I mean by this is that sooner or later (most likely sooner), when the gains slow down, you will need to use more time and intensity than you are using right now. Gains come by exercising the penis with more intensity as time goes on. Thus, if you start out with a high-intensity and a big time spending routine, then you will have to use MORE time and MORE intensity as time goes on. Not to smart, IMO.