Reti: Sicilian Invitation

I would like the help of more experienced players, as I have a little problem.

I usually start with the Reti (some call it Zuketort) opening as white - Nf3.

I usually follow with the Nimzo-Larsen attack (2. b3 3.Bb2), but there are some openings that seem to completely mess with that plan. In fact, any line that involves d6, but I'm pointing the finger to 1. ... d6 and 1 ... c5. Against c5, I'm usually okay if they play d5 next. But if they play d6 and then e5, my castle and plans fall apart.

In your opinion, should I completely drop the Nimzo-larsen if it is not met with 1. .. d5? If not, which lines can I still be able to use 2. b3/3.Bb2?

Against the sicilian invitation, which is best to play? Does the early Nf3 helps with anything? 

Keep in mind that I'm still learning my opening repertoire, For now as white I usually go for King's Indian Attack or Nimzo-Larsen, (and as black the Nimzo-Indian and the Nimzowitch Defense).

So, in your opinion, how should Nf3 meet c5? What does take black out of his confort zone and into the game I wish to play?

I don't see any problem:

U can continue with 4. e4 or 4. Nc3.

Wanna go into unknown territorry ? try 2. b4 !? a strange gambit .