6702 11/16 in. x 3-1/2 in. x 8 ft. PVC Composite White Casing Moulding

I use a nailer and cut my joining pieces on a 45 degree angle, if they are not quite perfect, I use caulk to fill in the gaps.

I believe it only comes in 10 foot. But you can call the Pro Desk for a accurate answer. You will need the stock number and title for them to look it up.

Not that I am aware of. But, it would be great if it did.

I used this product as a crown molding, it worked very well.

It is made of a plastic, so I assume it would be OK for outdoors.

This product was scratched and twisted. Either stayed too much on the sun or was miss handle by the store.

Liquid Nails should do the job for you. Choose the product carefully and follow directions. Cut and place moulding before you apply liquid nails.

I did not paint it as I covered white walls. I did use use DAP Alex Flex 10.1 oz. White Premium Molding and Trim Sealant to fill in the corner cracks. And this, you can paint over.

I am not aware of corner pieces for royal mouldings 6702. But, if your like me, ceilings can be uneven and mitering is an art, but, I used a white moulding caulk and filled in any gaps in the corners with it, it works great and your miters end up looking professionally done. You don't have to get the 12 pack, it is available in single tubes. https://www.homedepot.com/p/DAP-Alex-Flex-10-1-oz-White-Premium-Molding-and-Trim-Sealant-12-Pack-7079818542/205030290