Firsty, these are all legitimate tactics - it is just mos decision not to duel people who use them (which i disagree with).
1) Word of Faith
i)can be removed by something as simple as a lesser dispel. People are only to happy to get a few caster levels for their "truestrike" and what-not, so why cant they get a few more and use dispel.
ii) Only really screws up those with a lot of dex ac. So your fault. I have a wisdom based character with uncanny dodge and blind fighting, and i can take a WoFing and survive.
2) Hiders (hiding more than 1 time every 6 seconds is CHEATING)
i) High spot counters hiders hide skill. Its nearly impossible for hiders to hide against me. For others I just cast either a Word of Faith on them, or simply cast improved invisibility/displacement on myself, and then laugh as they fail to hit me. It appears that the only people who winge about hiders are those who dont even add spot to their items - I have no sympathy for them.
ii) Hiders (dex whores as they are) usually have a crazy low str. A simple "iron horn", or usually even a successful "improved knockdown" (they all seem to be halflings for some reason) will usually leave them way open to your assault.
3) Hellball
i) One of the main useful features of hellball IS the knockdown effect. It will ONLY knock you down if you take more than 50hp of damage - so you can either take a few energy resist feats to counter it - or simply cast some kind of energy resist - and hey presto - no more knockdown. I wont expect to be seeing anyone who complains about it using this spell themselves, obviously
4) Storm of Vengeance
i) Takes time to cast - its not a free action.
ii) Is just the same as any other AoE
iii) Certain Builds are immune to stun - as are casters who cast certain spells
iv) Gets COMPLETELY dispelled by any high level casters dispel, or in fact a low level caster with "gust of wind".
v) Can be walked out of
vi) Is autofail on a 1 which will be removed in the next patch
vii) Does not lag the server - but does lag some peoples graphics cards - so be considerate as to how many times you cast it. In all honesty, its suicide casting it more than a couple of times anyway - not to mention pointless against anyone who is either ranged/part-caster. And as Mo said - you will suck when autofail is removed with the next patch.