d.MP to beat Blanka’s slide is really important. It fights good against his d.HP somewhat as well.
JD, hurricane kick is a high damage counter to the random ball. When you’re raged, JD, run up d.MK xx super fireball is the easiest punishment. Anytime you’re near a corner though, JD, run up d.LK xx shin shoryuken does huge damage.
N-groove I don’t like so much because you need meter to counter the random ball. Block ball, counter roll forward, close s.HP xx shoryuken or hurricane kick.
Use far s.HK against Sagat a lot. It really discourages him from abusing his far j.HK on you. I wish Ken had a move he could use like that actually. Either Ryu’s far s.HK or the old A2/3S far s.MK.
All of Ryu’s normal ground moves (including his primary far s.HP) have annoyingly poor range, so in order to play Ryu well, you really need to use the fireball well. f+MK hop kick is always tempting to try and get in with, but d.HP mashing beats it clean unfortunately. Use the f+MK mostly after a blocked d.LP to build up the guard crush and keep your momentum going instead. Ryu’s all about the guard break anyway. Run up, d.MK/d.HP xx shin shoryuken after every guard crush is too good.
You have the great run to close any gaps, so don’t forget to always keep bullying the other guy whenever you knock him down. Basic shoto mixups like whiff low short, throw or whiff low short, d.LP, d.LK xx super. Meaty close s.MK or meaty close d.MP are very useful. It forces a waking opponent to block so you can easily link a d.LP afterwards everytime. Mostly it’s knocking down the other guy in the first place that’s going to be hard in these matchups.