Sorry friend, it's good to see you back, but you can't do either of those things, nor should you. Webm is just sort of a black box sub application OpenBOR says "play this thing", and that's it. You are expected to do all the video editing in production time - that's kind of the point of a video playback. The closest thing you could try is a scripted screen that captures the video output and shrinks it. I'm not 100% sure if that will work on videos though. Even if it does, that's some pretty advanced scripting just to keep an oversize file hanging around.
Same deal for animated .gif files. If you want to make animated cut scenes with special effects like resizing, the best thing to do is use dummy stages so you can take full advantage of the engine's graphic suite with models. Honestly you shouldn't be using animated gifs for anything except other than super simple stuff like quick one or two frame clips. It's a throwback from the original BOR when we didn't have unlimited animation frames, colors, control, etc. to work with when making scenes.
DC
