You've recently changed your interface. The load button has disappeared and there seems to be no way to delete a video. Effectively you've turned a nice simple program/service into an unusable mess. WHY?????
I don't know at all !!! I need someone to fix it ! Its for youtube ! If you can't fix it though, does someone knows a good free screenrecorder for mac (in wich you can hear the voice of the guy with you on skype)
I'm sorry to hear you're not liking the new look, but perhaps I can help with a few things you're struggling with. When you say "Load" button, I'm guessing you mean a button to import videos to use on your timeline. That's this button here:
To delete something from the timeline, just select it, and hit the "delete" button on your keyboard.