Looking at the photo of your plane it looks as if the engine is mounted high. Is it a lot higher that you fuel tank that would cause your fuel flow problems as well as lean conditions that could be the root cause of you overheating. If the centerline of your tank is below the spray bar on your carb this would explain a lot of you issues. If it is try going to an inverted mounting, I do believe this was Andy Lennon's preferred method of mounting an engine and this would cure your problems.

P.S nice job on your plane.