My H1b began in October 2015. I recently started process for GC (EB3) and am filing for PERM later this month. Priority date is Oct 16 as of today.

I have not traveled to Nepal for H1b stamping yet and do not plan to do it until I get my GC, which gives me two questions.

1) The first 3 years of H1b expires in Sep 2018. Is this enough time to get through the EB3 process and get my GC?

2) Is H1b stamping required for any step during EB3 GC application?

1. If you do not get audit in your perm and if you do not get major RFE in I-140 and I-485 then you will definitely get green card before September 2018

2. If you do not travel outside USA, then you don't need stamping for your h1b

1. If your H1B started on Oct 2014 then you probably meant to say, the first 3 years of H1B expires on Sept 2017 not 2018. In this case, it is definitely not possible to get GC by Sept 2017. PERM by itself takes about 5-6 months.
2. Like NE_Patriots said, H1B stamping is not required.

@Madani. Typo on my part. My h1b began in Oct 2015

from scratch to finsih put about 1 to 2 years of timeline. Depends on the company/ manager and uncle sam. Some companies do not need to advertisement / prevailing wage since they already have job postings or wage determination from other applicants.

If that is the case perm (3-5) months, 140 PP(15 days , 30 if RFE ) , 485(5 months)
Shortest time = 10 months Plus additiional 2 months for paperwork inside company.

Again this is if all the stars align right, 30% of PERM cases are in audit by default for QA purposes, if so add 18+ months to it.

After filing 485 you should get an AP and work permit in about 30 -60 days so that might help your H1b dilemma.

@ fdpowder: did you really mean to say add 18+ months on top of the 1 year process in case of a PERM Audit?

yes in case of a perm AUDIT. Not RFE , rfe is different and take about a month or 2