The new 18-55mm lens: the only lens one needs?

To make a long story short, i am a computer scientist with music as a passion and photography as an hobby. Since it is an hobby, i am still a beginner after many years, and after moving from a Yashica FX3 to a Canon G11 (with a short break on a Sony R1).

I am considering the X series, because of the user experience (between others): when i am out of the office i do not want to use something that remind me of a computer. And i am considering the X-E1 with the zoom kit because it is relatively affordable (the X-PRO1 with three primes would be hard to justify financially for an hobby :).

I followed this thread with a lot of interest; at the end, one of the reason to evolve from the G11 is the very reduced control of DOP and limited options you have on it.

So, what would you suggest for a beginner that want to evolve and learn (and that do not in general make photos at friends wedding) ? Better start with a prime and learn how to use it properly before moving to something else, or better the kit lens, that will anyway take years before being a restriction in learning ?

Thanks for your informed opinions,
Maurizio