"the games got way too many overpowered weapons, off a 100hp spawn you can get killed in 1 hit by hammer, flak primary or secondary, big goo, any rocket variation, sniper headshot and shock combo, with the power of these weapons spam is pretty ridiculous and a heavy attacking strategy is pointless as the run away spamming anything you got nullifies it everytime."
For an instant kill, the Impact Hammer requires full charge and melee range, Flak primary requires close range, flak secondary requires a direct hit, goo secondary requires full charge and a direct hit (or walking over it), rocket (mostly true) still needs a direct hit with one or multiple charged up, headshot is self explanatory, and shock combo requires you to shoot a slow projectile towards a moving target and hit said projectile while (predicting or hoping) a player's still in the same spot. For one hit kills, there's conditions that have to be met that can be avoided, of course some players can just predict movements to an insane degree.
One could also argue that by having all the weapons "overpowered" none are really overpowered.
Jokes aside, If you play FFA DM (not saying you do or don't) it can definitely seem that way because FFA DM is always just a blahfest (especially in larger numbers), but in TDM or 1v1 or CTF. The weapon balance is actually *superb* especially in comparison to UT2K4, which due to the dodge jump and maps designed around it (really wide, lots of visibility), hitscan was all you wanted. Watch a demo of a UT2K4 match or frag video and it's 40% shock rilfe, 40% lightning gun (UT2K4's play on the sniper rifle), and 20% mid-air rocket/flak/goo/grenade shots. In match demos, replace that 20% with using the minigun or link secondary to finish off an injured opponent.
And if someone runs away spamming...don't follow them, cut them off and shoot where they're running? Depending on the map there's bunches and bunches of access points and ways throughout the map. I'd say that a player who accurately predicts that someone's going to run down a hallway following them and attacks accordingly deserves the kill over someone just following them attacking heavily.