Can I state new causes of action without filing a motion?

If you were granted the ability to amend the complaint, yes, you can add new causes of action.

Can I take sue my previous employer to court even I signed the arbitration clause?

The answer to your question would depend on what the exact wording of the arbitration clause is. A full consultation would be necessary to...

As a Fargo, ND based business, would I have to register in CA as well to have an order shipment warehouse in Los Angeles?

If you are doing business in California, yes, you have to register here. Having a shipping facility sounds like it would be doing business.

Is there a minimum amount of days I should be scheduled in a 2 week period ?

Assuming that you are an at will employee, no, there is no minimum number of days you need to be scheduled.

Should I set up an LLC or S Corp for ecommerce?

An LLC is likely better, as it has less corporate formalities to maintain. As far as the second issue, you should consult a cpa.

If I take the Motion Off Calendar and refile it, as suggested by Mr. Parikh, would I lose my original date of filing?

No, it would be refiled as of the new date. It would not be considered filed as of the original date.

How to end the partnership?

You can file for a dissolution of the day partnership.

Can work have different vacations and policies for employees?

As long as the vacations and policies are not being administered in a discriminatory way, yes, this is legal.

A client may, but it could lead to a breach of the privilege.

I want to continue the hearing date of my motion to tax costs. How to do it?

You would have to get the other side to stipulate to this. Alternatively, you can take the Motion off-calendar and refile it with a new date.