why use a Sniper rifle when you can use a pistol? why use an assualt rifle when you have a pistol?
seriously, it was stupendously broken in the original and i dont think they toned it down enough! the pistol should be a reserve weapon, not a main weapon. It should be a starting weapon so you arent that powerful as soon as you spawn, and it should just be used for reseve so you can whip it out if you happen to empty your clip of you main weapon and still havnt killed your enemy.
the pistol in the original was basically so poweful that every other weapon was obsolete if your opponant had a pistol. it was a sniper rifle, a close range, a medium range, and it reloaded quickly, the shotgun was useless because if your opponant had a pistol all he had to do was back away from you while firing. the sniper was useless because it could only hold four rounds a clip so you had to aim well, but if you had a pistol you could zoom in and just fire whenever your opponant pops his head up and not care about ammo since the pistol holds 12 bullets a clip and can carry 124 in reserve! plus it had pinpoint accuracy, there was no deviation from the crosshair!
and to top it all off, it was a one hit kill if you got a headshot.
if you dual weild 2 pistols they are still very dangerous, try it sometime.
Pretty much all of the reasons you gave for hating it are all of the reasons it made my pants go crazy.
Anyways, I think the analysis depends on whether you are playing the game or on multiplayer (Halo 1). During the game, the pistol is awesome, but not so extraordinarily powerful that you can't use anything else. Pretty much any other weapon, or combination thereof, can get you where you need to go, and leave much death and gore along your path.
On multiplayer, the pistol rocks also, but they are not even close to invincible. A rocket shot to the chest, a well-aimed snipe (the fact that you lament needing aim to shot the guy down strikes me as odd, since for me the sacred aura of the sniper lies from his godly aim). I do admit that it is frustrating when you try to take one down with a shot gun (damn them.... who said they were allowed to walk backwards?) but a plasma grenade to the head and a hasty retreat should remedy that.
But yeah, for me, the sheer power of the pistol had me in awe, and now, after Halo 2, I cry myself to sleep at night. Although, to give it credit, when my dual SMG's ran out, my shield was blinking red and making that annoying, "you're gonna die, biatch," sound, and there were still two elites or whatever with a ravenous look in their eyes, picking up a pistol worked out well.