H1B, first NOIR and now RFE response review!

I had an approved h1b petitioned which never got stamped as i got 221(G) during stamping and uscis never gave an update on the case until last month(after almost 18 months) when they sent a notice for NOIR.

My employer has sent proofs now which USCIS now say that they are reviewing. My questions are:

  1. More than half of my h1b duration has crossed so I am not sure what benefit this will bring me even if it is approved. Would uscis increase my visa validity as it was never stamped and i never travelled on it.

  2. My current employer is willing ot file an h1b petition for me. how can i use this old visa for application into “cap exempt” petition next year. I need details here.

  3. if my current employer fills my petition on 1st april 2015 then would this “rejected and NOIR” visa have any impact on my that visa application? i remember uscis checks h1b visa history for an applicant.

Appreciate an early response.