First of all, thank you all for your long and thorough responses!
[...] I seem to recall someone doing a houserule, placing Riposte as a prereq for Djem So and making both of those talents better (like allowing Riposte to be used 1/turn instead of 1/encounter or removing the FOrce point cost of Djem So, or something thereabouts), although I cannot remember where I saw it, and my Google Fu is failing me.
I could see something like this work out, but I'm not sure about dropping the FP cost. Maybe Djem So would expand the uses of Riposte at the cost of a FP each time after the first in an encounter? I think StevenO suggests something similar as an option to improve Ripost.
Counterpunch is a good talent. It does require a few extras to really shine (like Combat Reflexes and the Melee Duelist talent Advantageous Opportunity), but so does everything. It's major downside is that it requires someone to attack you and does nothing against Force powers. I have a Sith Apprentice NPC that uses a lightsaber pike along with the talents and feats mentioned here to fend off multiple lightsaber wielders.
I think you are talking about the talent Advantageous Strike, but your reasoning about how to get the most out of this talent is sound. If combined with something that let you get an AoO and stop anyone from getting away, it could be even better!
As for Riposte, that book came out before lightsaber form powers. As originally intended it's probably not that weak, but became second rate after JATM came out.
Yes, I had an inkling that there was better options that could do this. I have to look those powers over once more. Yes, Fluid Riposte and Makashi Riposte do similar things without the investment in talents.
Ripost: 1/enc make lightsaber attack against opponent whose attack you used Block to stop
Improved Ripost: Block attempt that triggered Ripost does not count toward cumulative penalty. [errata removes 1/turn]
Djem So: 1/round when hit with melee attack spend FP to make attack against that opponent.
Counterpunch: When Fighting Defensively any attack by adjacent against you provokes AoO.
How nice of you to sum these up for us all!
The "I kind a like them" actually points to their power maybe not being so far off for what they do. Ok, Improved Ripost is pretty much complete crap but it is there to mirror Improved Redirect; sorry to say this but we really should not expect everything we see in the supplements to be great unless we wanted to see huge amounts of power creep in the game which I'm glad we didn't.
Yes, none of the three talents are bad, they are just not all good either. But I still don't appreciate talents that are: "complete crap"! :-D So, Improved Redirect would probably need some love from the GM before anyone would use it in play. I could see Improved Redirect have an entirely different effect like a potential persistent condition if moving the target down the DT.
Djem So is certainly an interesting talent. With it you're basically saying "my melee attacks are better than yours" and willing to spend the FP to gain additional attacks. You really should NOT figure on using this every fight but when you do want to use it I'm afraid but I do think spending a FP to gain an additional attack, even if it is under specific conditions, is a pretty powerful thing.
Yes, maybe the most interesting talent of all three, even with a FP cost.
It is late, and this is the best I could come up with in short time. I will take another look after a good nights sleep .