A few points I’d like to bring up.
You mention Dwn MK xx Hadoken as a combo. Yes, this is a combo, but sometimes even unsafe when it hits. A lot of characters can counter this easily with a rush type move or a super.
Standing HK is great against Hugo, Urien, Alex, Dudley to keep away.
I tend to use it the most against Urien or Dudley; against Urien, it’s a safe poke after knocking them down. Urien tends to panic a bit if they are cornered and knocked down, and a lot of them wakeup with LP Headbutt. You can use LK hurricane to counter that, or DP, or block, but I use stand HK because it is lower risk than LK hurricane.
Denjin: Blocked MP Dragon punch xx Denjin pushes the opponent farther away than LP Dragon or HP Dragon. This is useful to set up Denjin, imo
Lot of mixups after a landed EX Joudan kick. You can dash under and crossover. I’ll try to look for a Youtube clip
edit: Ok I can’t find that Youtube clip, but it’s Ryu fighting Ken, Ryu hits an EX Joudan, Does standing HP, fakes out, dashes under Ken, beats Ken with a Stand HP into Dragon Punch. Ken blocked the wrong way. It was an amazing finish.