Opt 1 :
a. Any one of you can do it. It requires many forms to be filled by you as well as your employer. Both of your participation is required. Its not a simple fill and submit form from employer. It requires quite a lot of internal details which your employer needs to provide such as registration number, turnover etc.
b. OINP Foriegn worker stream is a Paper PR process and will take 15-19 months at max if your application is straightforward. Once you get OINP nomination, you can apply for PR immediately and parallelly apply for Work Permit. Since its intra company transfer, I guess you would be LMIA exempt, for work permit. OINP nomination also makes work permit LMIA exempt.
c. Spouses usually get an open work permit. He/She can work anywhere and getting a job is purely merit based.
Opt 2:
Calculate your scores simulating 1 year experience. If its near 470-480., then you may take a chance and wait for an year as EE is faster route. However be prepared to go through the WES and IELTS process.
c. Spouse work permit is usually open, irrespective of PR. No issues.
Which path to take depends on your repo with your employer, the duration of your assignment, yours and your spouse's age, English skills, NOC code and many other factors. Its difficult for anyone to suggest a path. But if I had to pick one, I chose another route -> Come to Canada on Work Permit and see the local market for yourself and your spouse. If you like the lifestyle etc, then use the local employer's help (Canadian branch) to apply for OINP. Then slowly but steadily complete the PR process.