help pls--> PR Application ONLINE

jerseycharm

hello po! We are under 457 visa now and will start lodging our PR application online on November. (hubby's 2nd year on his employer).
I just want to ask for some info regarding the following:

1. Difference of visa 186 & 187, which is better to choose?
2. I already created an immiacctn on https://online.immi.gov.au so we can start lodging our application. However, upon entering my hubby's details, I cannot find the "Dependents portion" where I can input my details and my daughter as well. The only option I found was "New Applicant". So, I clicked it. Bale 3 applicants kami under 1 immiaccount. (pls see attached pic). But I am not really sure about this. Any advice please?
3. For the documents required, I have all original copies and scanned already. Are the documents to be attached needed to be certified first before scanning? If so, saan po pwede magpacertify?
4. How long the PR application processing/approval would take?
5. Finally, aside from the cost posted online, is there any other additional expenses that I need to expect? :-) (medical, certified true copy, etc.... mga magkano po aabutin lahat?)

Pasensya na po sa dami ng tanong, sinulit ko na po ang post ko. :-) Maraming salamat po in advance! God bless us all!