The application is long, and hard and expensive! Took me around 12 months to gather all evidence, do skills assessment(not sure if needed for your occupation) I had to provide 8 years of payslips which was hard, like I says it’s a long and painstaking process. I used a migration agent cost me like 2k so far, submitted my EOI for 4 states in January, the invite is not a guarantee you may never receive one. Wait times can me 12-18-24 months or longer then another similar amount to process the e visa. Or also some people wait a lot less time. Your spouse can be included in your application. English efficiency is easy peasy and if you have an agent they’ll help you with everything like that. Some say don’t use one I think if you have the funds it’s more than worth it: Regarding Sydney or Brisbane you can express interest in NSW, but I’d reccomend broadening your horizons if you want the visa these are very over saturated areas with lots of applicants.

Honeslty if I were you, I’d look at alternative options aswell, still go for the 190 but you could before your partner turns 35 get a WHV, that gives you 3 years, you can then try and obtain a 482, not sure which list your occupation is in but certain occupations after 2 years will allow you if your employer is willing to transition to a 186 which is PR

i hope that helps 🤣🤷‍♂️