Yes. The consulate will begin only after your fee has been paid and your biometrics have been collected.

Your record is transmitted electronically, like email, so it is virtually instantaneous.

You can try to change your appointment by selecting a different centre. You can also try to see if a different biometric centre can take you without an appointment, but there are no guarantees that this will be successful. A British consulate will not expedite an application simply because you have booked a flight; and we have always advised that flights should not be booked until a decision has been made and your passport has been returned.

Biometric enrolment is usually outsourced to 3rd party contractors although a few posts in smaller countries still have the equipment and can enroll you. In larger countries, this is not an option.

All of the costs are included in the application fee paid to the consulate.

On a site like this, it doesn't matter. It is the right thing to do for those seeking an entry clearance to the UK because without biometrics, the application will be refused.

Because both governments believe there is a mutual benefit to doing so.

False matches occur when your biometrics match someone else's. The theoretical probabilities of this are small, but computer glitches and inaccuracies wrought from using different equipment raise the chances to a visible level. False matches are currently dealt with manually on a case-by-case basis.