Technician's single pistol build works because the pistol damage is always maximized. A technician is also likely to have a powerfully modded pistol; if you have even a single powermod on your gun, you will do knockback with every shot against nearly every enemy, and will almost never miss because of Eagle Eye. SoG improves firing rate, so you'll put a pile of shots into anyone before they manage to get close and keep them at bay at the same time. Being a single weapon means you don't need both hands, so you can use an ammo box for rapid reloads, which reduces one of the biggest problems in pistol builds. The build takes time to hit it's peak, but when you're there it gives you a hideous amount of control over the battlefield. You can literally push around anything short of the Cyberdemon or Spidermind.
DW hits the sweet spot earlier; DW is available to anyone as early as level 3, instead of level 7. You double the damage you've been doing, right there. It doesn't come as a single attack, so no pushing enemies around the battlefield, but you can more easily KILL them at that point than a Sharpshooter could.
Anyway.
1) Dodgemaster: If you move in a direction other than directly toward/directly away from an opponent that shoots at you, they can miss based on your dodging chances (and some otherstuff). Dodgemaster makes it so they WILL miss, automatically. Just move as you want, and as long as it wasn't in the direct line the enemy was shooting in, you'll be considered dodging automatically.
2) Reloading while you move requires Shottyman (for shotguns), and it's automatic. Otherwise you reload by pressing 'r'.
3) "Running" is essentially a power-up mode you get by pressing tab. You get extra dodge chance and take less time moving between tiles, but your accuracy and melee-attack damage go down. Eventually you get tired and things go back to normal, and can't use Running again until you either get to the next level or use a healing item. This is not the same as just moving normally.