as often as you need them. Seriously though, about 2 years or so depending on your mileage and driving habits. I'd say about 50-70 thousand miles.
no
If you want to know if there is somewhere you can get instruction on changing brake pads because you need your brake pads changed, then the answer would be yes.
Radio presets and the clock.
No
If you're only changing the pads, no. You only need to bleed if the hydraulic system was opened or if you wish to flush/change the brake fluid.
Check brake linings - maybe need replacement
Yes
From what I know (doing my own troubleshooting). It means you need to take it in to get your brake pads replaced.
Yes, you do.
They either need to be adjusted or they were not properly reassembled. See the related article for adjusting and changing this brake.
Handbrake needs adjusting or brake pads need changing but i'd look at the handbrake first.
Dot 3 usually. It's written on the cap on the master cylinder if you need a reference point.