Earlier today, Mauve (the person who has been maitaining MBCaster since Tropsy stopped working on it) released a tool that allows the user to view all manner of minutate in regards to the animation in Melty Blood. It shows collison boxe, hit detection boxes, block levels, hitstun levels, and all sorts of other details that would excite any obsessive-compulsive player. Use the data to fine-tune your spacing and possibly find some obscure property of a move to further advance your game.

You can get the program from Mauve's official site.

Now I can sleep better knowing just how high I have to be to avoid Satsuki's anti-air grab.

It is also worth noting that the last update to MBCaster was released on August 13th. This features mainly bug fixes, but if are running on an older version (since it was originally thought he was done with development as of December of 2007), you probably should update. The full changelog is available from his site, along with the program itself.  You can also read about the latest update on Melty Bread's forum.