The one 2x4 that’s notched might be connected to the other webs that form the truss? If that’s the case I wouldn’t be removing that one. It’s hard to say what the red one is doing, is it directly below a roof joist that makes up part of that flat roof section? You could pull it out (the building won’t fall down) run another plate on the top about 30" long and add two new boards 24" apart and that would be sufficient.