leadwork

[sweetorb]

hi

im building a door / frame with some columns either side of it with a flat "roof" above, sort of a "facade" like you see on manor houses etc, picture a fire surround type structure around a door and frame with the "roof" being the mantlepeice!
i dont anticipate the finished flat roof section being much more than about 2400mm wide and 300mm deep (front to back) and formed out of marine ply fixed to a timber frame.
being a joiner and not a roofer i have no problem with the door and frame , thats made, but i was thinking of having a go at the leadwork that sits on top, tying into a mortar line of the brickwork (presumably with some sort of tilt-fillet to give it some sort of form where it meets the brickwork?) and being formed around the corners of the front and side.
my main questions are:

do i "stick" the lead down with anything i.e silicone / bitumen etc?
whats the best tool to use to cut lead in a tidy / straight line?
how are the corners formed?, i can only picture the as ending up folded over like a "hospital-corner" on a bed sheet!

and finally....is this something i should even be attempting???

cheers!