You need to learn how to hit confirm. I would go into training, set block to random and cover your eyes and listen to the sfx.
Nash's St.LK is his best wake up button, never wake up Genocide Cutter. If your opponent miss time their meaty, you can use Nash's target combo. Also it beats Urien Knee Drop.
When playing against a character like Balrog, Knee Bazooka will beat his Dash Punch and is +1 on CH.
For meaties, always end your combo with a M Scythe mid screen. On both quick rises, you can dash forward and use F.HK. If your opponent like pressing buttons then you can do something like this...
And if they do not quick rise after the step kick, you can dash forward and meaty with St.lk and combo it off with MP. You also want to use St.LK as a meaty tool on knock down and you can use it to tick throw.
Nash's CA him at ADV. You can dash forward grab or B.MK. What I always do is walk slightly forward for a meaty overhead, whiff Cr.Lk and do a sweep. The success rate is 95%