The brakes need doing as you wouldnt want to be heading towards stationary traffic at 70mph when they fail!!!! that would be the first thing, changing the timing belt is important as if it goes it does alot of damage to the engine meaning you will either need a rebuild or replacment engine. replacment engine cheaper!

As for the rear coil spring and coolant cap, rear spring could cause problems if it snaps with any kind of force at speed, the coolant cap isnt important enough to worry about but id pick one up from a scrap yard.

Hope this helps