When I do my TKstrikes, I use either hk or lk. I don’t think it really matters which one you use since your so close to the ground anyways.
as for which strikes to use in a situation.
HK- I use it for moving in closer to your opponent, after a block string, or just when i want to keep the pressure going. I use hk cannon strike the most out of all the divekicks. it’s also works good if you wanna cross up your opponent.
MK- pretty much the same thing as the HK, but i hardly use mk when cannon striking. i think i probably only use it on their wake up.
LK- you can use it to bait uppercuts when you jump over fireballs, or after a cannon spike. you can also use it for spacing too if you want to keep your distance. when going in with lk strike, i use it to fake a cross up on a back throw or if i want to hit their middle-lower body section. it’s most likely a guarantee 2 link hit if you go for a hit around that area.
also lk cannon strike works best after a spiral arrow knock down. it’s stuffs out uppercuts from pretty much all the characters like akuma, sagat, ryu, ken, and cammy.
for your last question, i always seem to end my combo’s with HK spiral arrow cause if I mess up my combo’s, i can FADC out and not worry about getting punish or you can continue putting the pressure if you have the momentum going.
i think MK arrow is stronger then HK arrow on certain characters if i’m not mistaken? i’m not to sure though
but it’s always good to mix up it up with lk or mk arrow once in awhile, cause you can go for a hooligan tech trap after but i hardly put it to use now days…
EDIT:
also to add about TKCS in her mix-up game. When I manage to score a spiral arrow knock down. I always spam 1 TKCS immediately after the arrow combo. When I do 1 TKCS it gives me the timing on when to attack or block when they do a tech knockdown. If they don’t tech, i do 2 TKCS on their wake up…
so if I wanna be aggressive, i’ll follow up with a block string. it beats most of their normals since it counts as a counter hit. you can also do another TKCS if you want to. so tech knock down- 2 TKCS non-tech knockdown 3 TKCS. if i know their gonna wake up uppercut i’ll just block and punish.
TKCS is one of her best pressure tool. Also, good for building meter, or if you wanna turtle and be unpredictable.