I've got some questions. I've been on my week of Dudley even though I've dabbled with him since Super.. never played him seriously though and probably won't.
Anyway, what are you favourite target combos to use up close? Also which ones can you link together?
Also, why is Dash straight so much harder than doing a Dash Upper after an exMGB?
Which do you go for after a exMGB in the corner? Dart Shot/Sweep/DP/Dash Upper etc?
The only target combo that I like to use in pressure is st lk xx st mk. It's -1 on block but +4 on hit so you can link off it. I use f mk xx st mk xx st hp to break focus up close and cr lk xx cr mp xx cr hp on Honda's wakeup since you can link st hk on hit and it will beat reversal buttslam. Other than they don't really have much use.
Duck straight is hard to juggle with because of how timing intensive it is and the hitbox of falling characters are. There's a window for you to cancel the duck animation into the straight that you have to be really on point with, and some characters have narrower falling hotboxes than others, making it even harder. Shotos, Bison, Honda, Grapplers and Dhalsim are particulalry hard to juggle, while characters like Balrog (the easiest), Cody and Viper are easier to juggle. It takes a lot of practice to get it down, and even then it's hard to get it anywhere close to 100%.
My juggle of choice in the corner depends on a lot of things, but as a beginner Dudley the best option should be lk duck upper. Upper has a really big hitbox, which makes it a lot easier to juggle with, and gives you a 5 frame safe jump (forward dash then hold up+towards) if they quick rise. When you can consistently hit that then you can move on to more damaging juggles like cr hk xx 2, duck straight to lp mgb and ex duck straight loops. If you're going to do ultra though, the easiest option in the corner is cr hk > ultra II, don't do duck upper > ultra.
Hope that helps!