Complete newbie to the epub forum here. Hi.
(Please don't kill me with sheep.

)
I'm really liking my new Sony reader, but I'm astounded to see that there's a high variation in embedded fonts and margin sizes in my epub collection.
I'm kind of a control freak, so I'd like to strip out the embedded fonts on all my books and force them to conform to my device-font. And while I'm at it, I wouldn't mind ripping out the predefined margins, because some of my books have a wasted inch of space or more. Ick.
I know just enough about epubs to turn the .epub extension into a .zip extension and look at the .css file. That is it. I know what CSS looks like, but have no idea what does what or what I need to change, etc.
So...
1. Is there a program (Sigil? Calibre?) that will let me change my epubs or do I have to modify them through the zip file --> css method?
2. What piece of code is in the epubs to override my device fonts and what should I change it to so that it will stop overriding my device?
3. Same question, but about margins: how do I modify them?
4. Is there a way (please dear god, let there be a way) to automate this for my 350+ epubs or must I do all this by hand?
Thank you in advance.