No.  You will be automatically categorised as a significant third party on the Transparency Register.

No.

If you meet the definition of a significant third party, you are required to register as a significant third party within 90 days of becoming required to register. If you are required to register, you must complete an Application to register as a significant third party an submit it to the AEC.

Yes, you have 30 days after being registered as a significant third party to lodge a 2020-21 significant third party disclosure return.

You can only continue to fundraise or incur expenditure once you are registered once you are registered as a significant third party. A person or entity that is required to be registered in a financial year must not incur any, or any further electoral expenditure or fundraise any, or any further amounts for the purpose of incurring electoral expenditure in that financial year until they are registered. Penalties apply for non-compliance.

From 1 February 2022.

In summary, electoral expenditure is expenditure incurred for the dominant purpose of creating or communicating electoral matter. See the fact sheet for details.

In summary, electoral matter is defined by the Commonwealth Electoral Act 1918 as matter communicated or intended to be communicated for the dominant purpose of influencing the way electors vote in a federal election. See the fact sheet for details.

Whilst it is not a mandatory requirement for you to lodge a nil return, it would be appreciated.

2020-21 member of the House of Representatives and Senator returns will be published on 1 March 2022.