First of all, remember that in Dustloop we use the "Calculator" notation:
7 8 9
4 5 6
1 2 3
So, in your first phrase would be 236A (spring dash A), j.236D (D kunais).
Second, in the same phrase, the is combo is finished with j.236C (C kunais), not with j.236D (D kunais), because the enemy is very close, so the D kunais will whif.
And third, though i don't really know weel the Yosuke's mixups, so it's up to you how to do the Blocktrings. You should check out the P4U section in the Dustloop Wikia for information about his moves (http://www.dustloop.com/wiki/index.php?title=Yosuke_Hanamura_(P4Arena)) and the Frame Data (http://www.dustloop.com/wiki/index.php?title=Frame_Data_(Yosuke_P4Arena)) to see how any of the Yosuke's moves can be followed. For example, 5B is good in blocktrings due to be plus in block (you have frame advantage over your enemy) so after 5B, you can use other moves faster that your enemy.