Thank you all so much for your input. We are 90% sure we will now lodge offshore and also through an agent here in London as to get everything spot on and by the book.
One more thing, where I am reading here: https://immi.homeaffairs.gov.au/visas/getting-a-visa/visa-listing/partner-offshore/provisional-309#HowTo it states that 'if you are married provide your marriage certificate. If you are de facto, provide proof of your de facto relationship.' Does this mean we will not have to supply the following points listed on the website as follows because we are married not de facto?...
Your relationship with your partner
If you are married, provide your marriage certificate or other evidence that your marriage is valid in Australia. If you are a de facto partner, provide proof of your de facto relationship.
This proof should show that:
you have a mutual commitment with your spouse of de facto partner to the exclusion of all others
your relationship is genuine and continuing
you either live together or don't live permanently apart
you are not related by family
Tell us in writing about:
how, when and where you first met
how the relationship developed
when you moved in together, got engaged or married
what you do together
time you spent apart
significant events in the relationship
your plans for the future
Finances
Show us how you and your partner share financial matters. You could give us:
joint mortgage or lease documents
joint loan documents for major assets like homes, cars or major appliances
joint bank account statements
household bills in both names
Your household
Show us how you and your partner share domestic matters. You could give us:
a statement about how you share housework
household bills in both names
mail or emails addressed to you both
documents that show joint responsibility for children
documents that prove your living arrangements
Social matters
Show us that others know about your relationship. You could give us:
joint invitations or evidence you go out together
proof you have friends in common
proof you have told government, public or commercial bodies about your relationship
proof you do joint sporting, cultural or social activities together
proof you travel together
statutory declarations from your partner's parents, family members, relatives and friends about how they see your relationship.
Commitment
Show us how you are committed to a long-term relationship with each other. You could give us:
proof you have knowledge of each other’s background, family situation or other personal details. You could tell us this at an interview
proof you have combined your personal matters
the terms of your wills
proof you stay in touch when apart