I would think that at WOT the plane would climb. I try to trim mine at half throttle for level flight. Regarding the running issue, you might try and remove the needle valve completely and put fuel pressure on the line going to the carb to back flush it. If it had been setting for some time there might be a speck of dirt, varnish or something that is causing it to not run right. Also what about the LSN have you adjusted that?