You guys've gotta give rendering a real go, and then you won't be complaining about the explosion and the beam, you'll be praising it.
Especially for something completely done in MAX - no touching up whatsoever!
Ryx, great work here. I'm particularly impressed with the depth-blurring you've put onto the out-of-focus Hecate. The beam, while not very FS-ey, is a very nice beam - the effect is pretty darn nice.
The explosions, also, while not particularly realistic, are not easy to make. My hat off to you - very well accomplished, and markedly better than some of my earlier attempts on ship explosions. Keep at it.

And that shockwave... well, that's friggin' beautiful. I
still haven't got shockwaves pinned down, to this day. The best I can muster up is something like this:
But, heh, don't mind that. Nice planet and starfield, too - they really fill up the pic, nice work.

I've got one big suggestion for you, which will change the face of the picture, and it's all about light (shadow also, but not so much in this pic).
The main reason
any picture will shy away from realism is because of light. There's not enough of it (rarely have I seen too
much light around here - I'd rather have too much than too little). Those explosions should have light auras - try to figure something out with MAX. The beam should also be washing the view with green, because a beam of that size isn't any little thing - it should have a forebearing effect on the entire image. (Light bleeding from the beam in front of the Hecate would be cool, but not necessary, and quite a difficult technique to master).
So, go overboard on the lighting. Because if you go overboard, you'll tend to get it just right.

(If you really
do go overboard, don't worry, we'll tell you...

)