The same way you get it to have a finite length 
Astromechs are actually fairly limited in what they can and can’t do. They’re here to plot lightspeed courses that don’t plow through stars - that’s their stated and major role, with a secondary repair task because the little guys can crawl where human mechanics can’t and operate in space without any issue.
Many pilots just also happen to use them as ad hoc autopilots, flight recorders, computer experts, amusing chirping sidekicks, what have you. But it’s kinda like using your phone as an mp3 player : sure, it *can *do that, but that’s not really what it’s for. FTR, Deetoo is a heavily modded one - your fresh out the factory R2 unit doesn’t have a built-in zapper, oil spewer, lightsaber flinger, jetpack…
That sort of makes no sense. If they’re just flight computers, why do they need wheels? All you’d need is a mac-mini-sized black box in the cockpit. And if they’re designed to be repair bots, why is their form factor so terrible for it? I can’t think of many places a rolling mailbox with no arms can go that I can’t.
For something with so many functions, how are people supposed to interact with it? R2 is shown understanding human speech, but its ability to reply seems pretty limited. There’s not much point in having something process information if it can’t communicate the results.
Ever seen 'em try to build an accurate shooting robot on Mythbusters? Getting it to hit the same spot consistently is hard!
If a protocol droid has storage space to contain six million forms of communication, you’d think all droids would have room to tuck away the six thousand most common languages is a small corner somewhere. Or even six hundred. Or sixty. Or six.
It likely has the memory but not a speaker.
You could say the same of Chewbacca, but Han apparently understands him.
And the explosives they were filled with was relatively insensitive, so without an explicit detonation, they were unlikely to explode on their own, even when exposed to heat and impact.
Maybe, but that wasn’t the weeapon that did. The magazines for all the standard pulse rifles were collected prior to that little extravaganza. The weapon that seems most likely to have done that damage was the M56 Smartgun, since Drake and Vasquez snuck some ammo past the sarge.
Probably already done, but I think the worst is the Fallout universe MIRV. The Fatman is bad enough, but I have never survived the use of a MIRV in actual combat (I managed to survive a few shots at it’s maximum range just for shits and giggles in Fallout 3). Even if you COULD survive the loot would be in a heavy radiation zone, and what good is it to kill mobs if you can’t loot them???
Honestly, I’m not sure you can compare the efforts of a couple of guys in a machine shop with a deadline and limited budget to the kind of technology and budget available to a civilization that can build a space station the size of a moon. And I’m assuming that blaster bolts and lasers are less likely to be affected by aerodynamic randomness than paintballs or darts which is what the Mythbusters are usually shooting.
Just suspend a microscopic rotating black hole out from the hilt and, Voila, scimitar!
They were experimenting with this for tank warfare, where tanks could recognize friendlies, and not shoot at them.
A bloke I know was working on something similar for hand-held firearms: the gun wouldn’t shoot unless there was an actual person in the line of fire. He bleakly referred to it as “murder helper.”
The Fallout 4 version of the MIRV is crazy. 6 mini-nukes. But that’s a mod; you can put that on if you want it (at the weapons workbench) or take it off.
A two-shot legendary version of a Fat Man can also be MIRV’ed. This is ridiculous, really. 12 mini-nukes, with concomitant reduction of throw range. I’ve had characters killed through injudicious use of such a weapon, when the spread of the MIRV effect put a few of the mini-nukes behind me. :eek:
With regard to making a lightsaber blade curve:
You always did look for the simplest, easiest-to-implement solution, didn’tcha. 
Actually, if a light saber is really a plasma sword you could probably make it curve…and probably do the basket hilt thingy too. How you’d protect yourself from the massive temps is another issue, of course…
Why look for an elegant engineering solution when you can just Force it?
Samus Aran’s power armor makes much less sense than Tony Stark’s. Huge shoulder pads that blocks periphery vision. Arm cannon covering entire forearm with articulation only at the eldow; how does she aim it, where’s the ammo stored? How does she and the suit fit into a 1-meter sphere? How the hell does she keep orientated jump-flipping everywhere?
Speaking of MIRVs, does anyone else remember the game Scorched Earth? Specifically, does anyone else remember the Death’s Head? And did anyone else ever set the explosion sizes to the maximum possible?
In all of the thousands of times I’ve played that game, I think I might have survived using the Death’s Head twice. But it was always worth it.