Will a JW be excomunicated for marrying a non JW

Answer 1

A JW can marry a non JW if they want to. They will not be excommunicated. I have met a few JW's who married "non believers" after being baptised.
Even so, it is not something that is encouraged.
In fact, the magazine the Watchtower (written and published by JWs) states "Similarly, yoked together by marriage, a believer and an unbeliever will undoubtedly face friction and strains. If one mate wants to remain in Jehovah’s love and the other cares little or nothing about that, their priorities in life will not match, and much discomfort is likely to result."
I have seen marriages go wrong a few times because one person was a JW and the other was a non JW. They have different priorities in life and so want to do totally different things with their lives.