For the first juggle, you cancel from the fierce slash into the jab one rather fast (this is why you do the jab one; it recovers faster), and then do st. fierce not quite immediately. AFAIK that particular juggle should work on everyone.
I think corner palm juggles only work on characters with wide falling hitboxes, like chun, q, etc. You can go: palm, fierce slash xx jab slash, pause, fierce slash x3. The pause is necessary to ensure that you don’t cancel the jab slash into a 3rd slash (the knockdown one), since after any slash except a knockdown one, there’s a period of time in which it looks like yang is in lag, but you can actually cancel into the next slash; you need to wait until after that period.
Also, I think on q, you can juggle with 5x ex slashes, but it’s harder to keep track of when to cancel into the next slash b/c you have to keep track of how he’s falling, i.e. since ex slashes are so much faster than reg. ones, it’s more difficult to space the pauses in between to keep hitting q.
In any case, just keep experimenting and watching videos; hope that helped.