Yes, of course! You can always learn them.
I don't understand exactly what your question is. I'm sorry.
Yes, of course there is. Above 19 is not a preferred age for you to audition for a company for the first time but there's no certain age limit so you can always try! Fighting!
Hi!
The number greatly differs from company to company.
There's no definite answer for this. They will call back whoever passes the first round of audition after usually a week.
Incomes and payments are different every month and for every contract. Different people receive different payments based on their contract agreement, activities, years, splitting, etc.
A member? Of a group? When members debut together, they'll have to stay together almost all the time so your relationship will grow through time even though you guys aren't on the best term in the first place. This happened to Minho and Key of SHINee too for example.
Think about what's your strength and what song or performance can show that strength the best.
Where you go first is something that you shouldn't worry about for now. The company will get you through everything. Most people are like that but you'll overcome it. Don't be discouraged over such things.