Okay, added some substantial material. Hopefully everyone's cool with it:
Clarified the range of EX SAB and basically warned off using Vulcan.
Tick ThrowsClark has perhaps the greatest variety of throw setups available to him aside from maybe Vice. He has three different kinds of grabs (not counting grab supers or Neomax): B SAB is slow but has autoguard, think of it kinda' like a parry. However certain moves, ex moves, and footsies will beat it. D SAB is your standard grab. And lastly you have his air grab (jump C). You're free to mix it up with these tools but here are some ways to land these grabs:
Jump in any attack (including CD), hold forward and quickly do standing A or B followed by B SAB.
A Gatling on block, then B SAB, works best on characters that lack an instant command grab. Very gimmicky but worth experimenting with.
Combo into A Gatling, followup A Gatling, jump toward D, as they land B SAB.
Empty hop B SAB (invulnerable to low attacks)
With D SAB jump in any attack, standing A or B, then you have to run and do D SAB.
And of course empty jump D SAB. Can mix this up with hop A, then empty hop into D SAB.
For his jumping grab the ticks I listed above will work, just and grab them.
The trick is to force the opponent to guess which way to block and if they should counter or not.
It is up to you how to use Clark and his command grabs.
Close RangeGeneral pressure
Hop A, crouching B then combo into D SAB or go from crouching B into crouching A and combo into A Gatling.
Hop A, crouching B, standing B. If standing B hits you can go into Hyperdrive mode or just do EX SAB and the followup drive cancel into Grab Super. If they block standing B you can do a crouching D or hop A or hop CD or just try to bait them.
Generally Clark's hop A is his best overall jump in. It will beat a lot of pokes to keep him out, it's fast, and it provides a lot of hitstun to combo into anything.
Best Jumping attacksClark's CD is really good but the problem is it's slow and will get beaten out, especially if you're predictable. His best overall jump ins are short hop A which is fast, will beat and/or trade with a lot of pokes meant to keep Clark out, and gives you a lot of hitstun to combo into anything.
Playing DefenseYou know what they say about a good defense right? Clark has the tools to keep his opponents off of him and can play a mean footsie game if he has to.
Neutral hop D will AA any jump in if you have the reaction time and it's very fast. I would not advise on jumping in with either B or D because they will not hit low and the risk is often greater than the reward.
Crouching C will AA nuisance jump ins like Billy's jumping C and Iori's jumping D. It will not beat Kyo's jumping down C though.
Standing A will counter virtually every hop coming at you if you're within close range.
And as mentioned Clark's standing D and C and sweep (crouching D) are amazingly good pokes, and both have slight AA capabilities. Standing C seems to AA slightly better but it's slow recovery can put you at risk if you get reckless with it.
Might want to experiment with Vulcan at about mid-range if you think they want to jump in, and will potentially scare them from trying to do so.
OkiClark's command grabs result in a hard knock down which gives you the opportunity of messing with your opponent in a big way.
After you land a command grab you can try the following:
Dash in, AB roll (can be delayed to make it seem like you AB Roll'd behind the opponent) and either: B SAB, wait and D SAB, crouching B into crouching A into whatever, or jumping grab, or just wait.
An example of what I'm talking about: (4 minutes in)
http://youtu.be/1tLdLCWQpoUI'm going to add matchups soon. There's not much to add in regards to setting up airgrabs, basically you want to scare them into jumping and grab them.