Skilled independent Visa for a nurse from the UK

Hi, I am a qualified paediatric nurse from UK. I am looking at applying for a skilled independent visa within the next year. I have a few questions about the visa if anyone atal could answer any of them.

Firstly i live with my partner of 4 years (not married) he has a trade but not at a level to use as his own visa so was wondering if i can have him on my visa with us not being married??

Secondly i have a mortgage in the UK, how long does the whole process of the visa take from start to finish so that i know how to sort my finances?

Has anyone moved from the UK to Australia? did they get a mortgage or go to renting?

How much money will i need to emigrate? for the paperwork and visas to actually moving including house, car?

In the future can i add people onto this visa? in 3 years my parents would wish to move to australia with me. Can i add them onto the visa as they do not have a trade between them and are both over the age of 45 so would i need to sponsor them or can it just be added to my visa?

Thanks in advance for any questions answered :)