Can I pass through my business loss to my W2?

Hello,

I have a W2 job and also I am an owner (one out of two) of a partnership company which does property rental business.

The business needs a vehicle. 

So my first question is: Could the business loss offset my W2 income?

My second question is: If I buy a vehicle over 6000 lbs for the business, can I write it off using Section 179? If the business loss can be passed through my W2 income, does it mean I can write off the vehicle cost from my W2?

My third question is: Do I need to use the Premier version or Home&Business version? 

Thank you.