Is a transfer possible from a cap-exempt to cap H-1B?
It is possible. You will have to follow the April-October time frame, except where you apply for concurrent cap employment to run together with your cap-exempt employment.
My H-1B status will expire the last week of January 2013. I cannot file my petition for an extension until after January 1, 2013. Will that be too late to file an extension?
A petition is considered to be timely filed as long as it reaches USCIS prior to the expiration of your current H-1B status.
I was in H-1B status for three years, then changed to H-4 status. If I want to change back to H-1, will I need to wait to file under the new quota?
If your previous H-1B petition was counted against the cap, you should not be subject to the quota and should be able to file an H-1B petition at any time. However, if your prior H-1B employer was cap-exempt, you will be subject to the quota.
The employer who is going to sponsor my petition has told me that I will be working in more than one work location. Will USCIS see this as a problem?
The petitioner (your prospective employer) will need to submit a complete itinerary of services or engagements if you will be performing services in more than one work location. Furthermore, the petitioner must comply with Department of Labor regulations requiring that an LCA is filed specific to each work location for the beneficiary.
If I am applying for concurrent employment on H-1, can I extend my status based on my new employment, or can it only be for the time I am already approved for?
You can extend your time, assuming that you would be otherwise eligible for an extension of status.
I may be travelling US on H-1B next year with my spouse on H-4. Is there any possibility to find a job in US for my husband through H-1B sponsor by some consultants and how much risk is involved in this?
As long as there is quota remaining on the H-1B, the law permits change of status from H-4 to H-1. And, if the H-1 is denied, that does not affect the existing H-4. So, no legal risk that I can see.
An employer applied for an H-1B for me two years ago under the quota and it was approved, but then I was unable to come to the U.S. to start the job. Can another employer apply for an H-1 for me now, or will I be subject to the quota again?
You should not be subject to the quota, because you were granted an H-1B approval before.