Strange Roof Framing - Are these ridge supports temporary?
My house is framed similarly, mid 1950's.  No I would not remove any of the &quot;temporary&quot; supports you've pointed out.  Like you said, the vertical ones are to help support the ridge board and keep it from sagging.  I have those in my attic also, and have even doubled up on some of them.
The long diagonal board is to keep the gabled end of the roof, and the entire roof for that matter, from &quot;racking&quot; and folding over in the event of a strong winds.  Without that brace, the entire roof structure acts like a un-reinforced square.  With the brace, you turned that square into a triangle which is much resistant to folding over on itself.