You can paint the panel. The surface will need to be prepared per paint instructions. Most say to scuff (lightly sand) surface so paint will stick.
It depends on the building codes in your area. It is 29 gauge and most houses are done in a 26 Gauge.
26 Gauge is available special order but is not a stocking item. It is sold by the foot. you can contact your local store for pricing.
Yes 8 panels will cover.
Yes our selection of flashings applies to this color
Yes you can overlap.
You would have to prime the panel first, then use several light coats.
Panels can be special ordered to the length you need.
The panels are not stocked in 4' Lengths but can be special ordered. The pricing will be higher since it is not a stock item. You may consider cutting the 12' panel.
Each store has a special order program in which they can order items that are not stocked. They do have minimums. You would need to contact your local store.