Aussie marrying an EU in UK

[Blakey]

Hi guys,
I'm currently engaged to a lass from Northern Ireland.
We are both living in Australia, but her visa for here runs out in December, she'll be moving back to N.Ireland then. The wedding is scheduled for July 2016 I will plan to join her in Northern Ireland before the wedding.
She also qualifies for an Irish passport.

My questions are:
1. What are my options for living and working in the UK?
2. Can she sponser me if she's an EU national living in UK once she gets her Irish passport? Do we need to be married first?
3. Would it be easier/cheaper for me to enter the UK if I get the marriage certificate here in Australia before she moves back to Northern Ireland?

Thanks for your help!

[vinny]

Best if you marry while she is in Australia.

1. If she is British, then you may apply for a spouse visa under the UK immigration rules or you may apply for an EEA family permit via the Surinder Singh route under the EEA regulations. However, for the latter, she must move to a third EEA country with you first, etc.

2. Some dual British/EEA people choose to renounce British citizenship to enable their family members to be eligible under the EEA regulations, without using the Surinder Singh route.

3. Yes.