http://www.projectrho.com/public_html/rocket/index.php

^Good starting point for hard sci-fi.

Onboard a ship trying to accelerate, 'down' is usually going to be towards the rear of the ship. Making the USS Enterprise a case of [url=http://www.projectrho.com/public_html/rocket/misconceptions.php#id--Rockets_Are_Not_Boats]Space is not an oceon[/url], stop using naval terminology in something that is more akin to [url=http://www.starfighter.no/web/hi-alt.html]dogfightiong a pair of X-15s and F-104s in ballistic traectories[/url]

After that, it really depends on whether you want Asimov/Clarke/Heinlein-style hardness, or some Trek-Warsie-Whovian fandom-aspects.

The vast size of space = Long engagement distances = It'll take several seconds for that keel-burning laser to reach you = plenty of time to do random jinking and hope they fry their own heatsinks first.

BTW: In Ender's Game... that ice-belt trick was mostly because in the book, back in battle-school, they used to work with battle-cubes ['stars']... the way you describe it sounds more like the primitive 'over tha top' tactic the old Salamander commander used. In the book, Ender's tactics got... a bit more !physics... (like deploying wires/becoming trapeeze-artists to change trajectories [i]by using the orbital-masses of their own ships[/i], aerobraking, and shooting the sun's corona [url=http://en.wikipedia.org/wiki/Gravity_assist]for an epic air-gravity-assist[/url], early-on, he learned to 'land' on a cube, but soon found it better to just vault from cube to cube at exponential velocities... [i]a 'toon consisted of 40 students[/i]...)

[u]In short, the way Ender fought in the book was less 'cover' and more 'Trapeeze-artists in a pitch-black tent with machine-guns, flashlights, and meatshields'.[/u]
-VERY FEW of his 'battles' lasted longer than three minutes and had the tempo of room-clearing/CQB.
*Which is why the admirals loved him. Because he and a bunch of launchies could outright [i]murder[/i] their well-seasoned and best tacticians in about the time it took to finish reading this post.
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Anyways, the ultimate deciding factor is how long you've got before you:
1. Loss of sensors (Cannot 'see') / Out of ammunition/laser-coolant (cannot shoot) / out of propellant (cannot 'move')
2. Start flying a predictable trajectory (Now easy to hit)
3. Deploy radiators (loss of armor-protection)
4. Loss of radiators/Saturation of heat-sink (there is one final way to dispose of heat... venting... but once you lose stuff to vent... well.. you'll either fry or decide you can afford to vent something else)
Damage-control teams can work miracles over time, but once you reach stage 4, life aboard the ship is usually pretty hostile to those guys.

Nuclear reactor meltdowns are unlikely, you can nearly always scram the reactor. Or eject it, followed by pulverizing it to sub-critical masses.
-But you may be so hard-up, that you're venting breathing-air to maintain a habitable crew-temprature. And if you've ejected the core, it's pretty much game-over until someone loans you a new one.