Any blocked Ice car is unsafe. (buffer 360/720 time)

Really only applies to Ragna, Jin, Litchi and Tager as well as the reaction of the opponent. I guess it also applies to Hakumen depending on the situation.

But one trick I love doing when a Tager does buffer a 214A (upon block) is to follow it straight into a 623C as they attempt to 720 if they didn't execute it fast enough.

Tager as does everyone with distortions, Can delay that (though typically they don't do it on purpose) to catch you through invunerablity with their delayed move. (lag causes this online generally more than player awareness)
Tager's buster also has a delayed affect before the invunerablity starts I have had it catch through jins trying to counter also.

Actually as per the Ice car on block esp Ib (any of the ones that 2 hit should be Ibed on the second hit esp local play) can make you pay for it. Remember Ib the second hit of Ice car (in the air) Distortion is 1 frame start so basically you will eat most distortions, unless Rapid cancel.

Also if you Ice car due to the delay, tager can before it hits at the proper height Magna tech wheel combo for 5kish depending on heat.

Basically any special move has bad recover time and can be punished hard.

If you become predictable with pressure Tager with even his slow arse, can J2C combo you for 4-5K, Or 2C or Collider catch you into a combo for 4-5k.
Granted this is typically depended on him having you A magnetised or B Sparkbolt up to net them that high other wise it will be 3kish range.

Bang, has one of the better pressure strings that you can repeat due to the safeness of 2369 D nails in corner that he can keep that pressure string up till out of nails (typically they will rotate it into a throw so be weary of it.)

By 1 frame start up? I don't think so because there are some frames before the freeze (like Ragna readying his sword before zooming in to CS). Maybe it could just be for Tager.