Surinder Singh Route, Zambrano or Domestic rules

Hello everyone,
I would like to know which route would be better/easy option in terms of applying to enter and stay in the UK on the basis of:

1.Non EU citizen married to British citizen.
2.Both have a child who is a British citizen.
3.British partner doesn't meet the financial requirements.
4.The family live together outside EU atm.

As Surinder singh requires residence in another member state so moving to another state with a child is not a child's play.

I have read on GOV.UK that if a partner chooses 10-year route to settlement then there are no financial requirements to be met. If that is the case what are the other requirements that need to be met as it doesn't show the full requirements on the website.

There is also a 5 year route to settlement as a parent for which the requirements don't look as bad as other options.Could someone please explain is this is the right route for me?
Last but not least, would I be able to apply under Zambrano if I fail to meet the requirements of other categories.

Thanks in advance.