The problem with resizing in Skitch (or using the Skitch tools built into Evernote) is that you lose the original image data when you resize it. Once you've resized it in Skitch, you can't size it back up to the original size again. Most modern apps let you scale images inline, and that scaling is lossless. (See Microsoft Word, Apple Pages.)
Regardless, even the current scheme in Evernote is not WYSIWYG. Images that appear reasonably sized onscreen often turn huge when you try to print them. I have lots of images in my recipes, and I find I can't print them since the images take over the page when printed; sometimes they even tile on to other pages. Try it, the current scheme is a bit of a disaster.
I've resorted to putting just one image at then end of each recipe so that I can use the recipe and discard the image if I need to (the image almost always generate a page break and gets bopped to the next page.
Even BBCode allows you to change the size of an image without losing any data.
No need to use Skitch. You can do it all from with Evernote:
1. Click on the annotate button in the toolbar
2. In the popover that appears, click on the image you want to modify.
3. Click the crop button
4. Click the resize button
5. Drag the slider until you get the size you want.
6. Click apply.
7. Close the annotation window
You now have a resized image which can be printed on a single page.