Thanks for responding, samboll. Sorry I didn't explain my questions clearly enough.
The Image Manager plug-in is a utility to edit the image styles: position, margins, padding, and placement etc., and then upload the image to the post box on the Write screen.
A fancier version of the standard built-in file uploading utility, it also lets you create pop-up thumbnails on your blog page.
I have two problems (difficulties?) using it:
First, after I edit the image in the plug-in module and send it to the Write screen or publish it, if I'm unhappy with the way the image looks, it's cumbersome to make changes. I can't just highlight the image (like I can with the built-in editor) and make quick adjustments to it. Instead, I have to call up the plug-in module, browse for the image, click it into the module, and re-enter all the styling info, and resend it to the write screen.
I was hoping there's a quicker way to re-edit images, instead of the clunky way it works now.
Also, I'm hoping there's a way to have more than one thumbnail pop-up window open on the blog page at the same time. The pop-up feature is nifty: if you click on the thumbnail, a window pops opens on the blog page, and you can drag it wherever you want. But you can only pop up one image at a time (if you send three pop-up thumbnails to the page, you can only toggle between them one at a time).