>Space is not a good place for an Eva. Without the E-Type equipment, they have a tendency to instagib as a result of decompression and flash freezing.
SPACE DOES NOT WORK THAT WAY
Ok, it's generally fine. Nobody cares about realism and the tropes are so entrenched, physicists (in training) like myself forget they're lies unless reminded of them on occasion.
First, explosive decompression doesn't actually make you explode. The term "explosive" refers to the rate of decompression you undergo if you jump out of an airlock, unprotected, into space. I.e. very, very fast. Anyway, being exposed to space for any significant amount of time will still be very unpleasant, as small cappilaries will burst, you cannot breathe (evas, drawing their power from electricity or other sources may not be bothered, as I do not know if they must respire or pass out). Anoxia sets in at around 15 seconds, death at around a minute or minute and a half.
Second: Space is cold, sort-of. However, vacuum is also one of the best insulators you can possibly find. Freezing isn't the issue at all. Overheating is. Since there's no atmosphere to carry heat away by convection, the only method of heat-transfer left is radiation, which is very inefficient. An evangelion would need to worry more about boiling its own organs or its pilot's, if it operated without proper radiators in space for long periods.
Also, most weapons would probably have overheat problems, and no solid-shell projectiles will function unless they're rocket-propelled and bring their own oxidizer. Gunpowder assumes there's an atmosphere with which it can react to combust, after all.