B1/B2 and TN application at the same time

[Kavyro]

I'm a Mexican citizen on a TN visa. My TN visa is about to expire and my employer has already sent me all the documentation to renew my TN visa. The situation is that I don't know how much longer I will be working for this employer, since I have a work proposal from another employer working from my country. My B1/B2 visa will expire on 2016 and I don't want to end without a way to enter the USA.
-Can I apply to renew my B1/B2 card while renewing my TN visa?
-Should I wait to renew my B1/B2 card?
-What am I suppose to do if I leave my current employer?

[inadmissible]

You can apply for a new B visa. Your life has changed alot since your last B visa was issued. You no longer have employment and residence to show as strong ties to your home abroad. The odds of receiving a new B visa will be better after you leave your job and return to your home country for work.

If you leave your current employer, you are supposed to go home. There is zero grace period upon termination of employment. Having a valid B visa will enable you to turn around at the border and seek admission for temporary purposes, eg to wind up your affairs. It may be worth attempting to renew your B visa now so that you have that option, but be prepared for a denial.