Might be an idea to get a new gasket for the intake/head connection, although mine (gasket) is sealed with blue gasket paste and its fine.

There is a very large o-ring that attaches to the bottom of the EGR valve (where the big pipe comes in). Get a new one of those.

Get a 2 metre length of return line. Its cheap and you might as well do it.

Get some plastic clips for the injector lines. They'll all be brittle and weak. They cost pence (cents in colonial money)

While you're at it, give the EGR valve a damn good scrub. It's very heavily sprung so get a mate to push it open for you while you scrub it.

To clean the manifold, you need a long bottle brush.

Be careful you don't drop anything in the pipe that attaches to the EGR. That would be bad....