Cohabitation Visa (Antwerp)

Anyone go through this process? I am from the US considering cohabitation visa with my g/f who lives in Belgium. She is a resident and works in Antwerp. So far my understanding is that I would need to head to a local office in Belgium to declare cohabitation. While that is processing it is advised that I do not travel for 3 months. I know about integration classes and I think I receive a temp residency card as well.

Some questions although I welcome any detail to the process:
Can I work while this application is processing?
Do I have health insurance through my g/f?
What are repercussions, if any, if my application fails? I am under the impression I can file again right away.

I was hoping to find work prior to entry but that seems impossible. What are the job opportunities like in Antwerp and surrounding area for English-speakers in the IT field? I am sure learning Dutch will help a great deal but currently I only command the English language.

Thanks for any help!