Crop & scale are only proportional??????!!!!!!!

I'm really baffled... but I hope I'm just missing something really simple... please help:

- so, I'm experimenting with iMovie 11 because I've been a Mac guy for 20 years. And, after making a simple 5 minute instructional video (for work) on WinXP, of course I discovered that Windows Movie Maker was a typical MS type program where you end up editing XML files... and you only get one audio channel, so if you want 2 audio channels you have to make a movie and then use that as input to another movie... don't get me started on Windows.

- the movie has video clips, still images, narration and a music background. A simple fade from scene to scene is fine.

- I made some text banners (a colored block with text within the block). I use these to block out background at the top of a video clip and to announce the subject of the video clip.

- In Windows Movie Maker (and, Wondershare Video Editor, which I purchased) I can overlay this text banner on a video clip. I can then crop, shrink, stretch that overlay to fit the way I want in the video clip. I'm fine with the text stretching or squishing a bit.

- I am amazed to find that I can't "stretch" in iMovie 11. I can shrink and crop. But those operations are ONLY PROPORTONAL. I need to be able to do a non-proportional stretch so that I get the proper width to include the text, and fill the width; and then stretch down/up to cover the section of background that I need to block out.

- I thought I saw a Youtube tutorial where they used a crop function where you could move each corner of the crop field individually (the other corners would remain fixed in place). So, I made a large banner with my text in the middle. I figured that I could overlay it in the video clip; and then do this corner-by-corner crop to get the banner that I needed to fit the way I need it to fit. Granted, this would be a cumbersome approach. But, I must have been dreaming because I can't find that cropping example again, and I can't find a way to get iMovie to do it.

- I'm guessing that the designers of iMovie are thinking that if you want to do what I want to do, that you take a screen shot of a single frame of the video clip that you want; bring that into Power Point (or some other graphics program); make a banner that fits that clip-image the way you want; put text into that banner; make a screen grab of that banner; save it as an image; bring that into iMovie as a PIP; shrink; and finally position.

- QUESTION 1) Is that really what I have to do? Please tell me that I'm missing a simpler approach...

- QUESTION 2) I don't understand why iMovie developers would implement "proportional scale/crop" but not also implement "non-proportional scale/crop". Do you understand why this was not implemented?

Thanks, in advance...