Geese is good for guard crushing and his best groove would be K groove or A groove. K groove is preferred because he has such strong moves that can guard crush and then you can get a level 3.
Raging Storm is helpful but not a necessity. In fact, don't try to spend the entire match to do the super. If you do get the move out, but it doesn't hit or you lose all your life, what's the point? The official motion is dwn back, hcb, dwn fwd, + punch but I just do hcb hcb + punch. I like to do it on wake up because it's safe or if I know that someone is going to jump. Honestly in my opinion, you use Raging Storm when you know it's going to hit.
He has good normals such as s.lk, cr.lp, s.fierce, cr.fierce, f + fierce, s.RH, j.RH and low jump mk or RH.
If you're close to someone, do s.lk, cr.jab, cr.jab, cr.RH, cancel to jab reppuken. It doesn't matter if it hits or not. If it hits good, if it doesn't, then it still does good guard damage. HOWEVER, (big however), sometimes your opponent can hit you during the recovery from the reppuken. I've have numerous times where someone got a free Custom Combo on me or a level 3 super. So be careful (some examples are Blanka's level 3 Direct Lighting, Sagat's tiger cannon super or tiger raid, or just fast supers. CCs can usually hit Geese but people can mess up so that by the time the invincibility wears off, they get hit by the reppuken). BTW the point of the reppuken is to cancel the recovery time of the cr.RH. It can hit people who use safe fall grooves and safe fall after they get hit by the cr.RH.
if you can get a cross up after j.mk, you can do cr.jab (or s.lk), s.fierce, Deadly Rave (hcb, f _ lk jab jab short short, mp, mp, mk mk) then instead of finishing it, do cr.jab (or s.lk), s.fierce, hcb + mk. Usually it can dizzy a 63 stun character or make it close for a 70 char. What you can do is run up, low jump mk so that they can get hit and get stunned. Then do cr.jab (or s.lk), s.fierce, hcb + mk.
DON'T do random Jaei Kens (hcb + k). It's slow and sucks without being in a combo.
Counters jab counter is good for high counters (like jumps), special moves (moves that require direction and normals) and supers. This is the best part of Geese's counters. It can COUNTER SUPERS! But keep in mind, it can only counter non projectile supers. So don't try counter Ryu's shinku hadouken. ever.
mp counter = good for s.normals like s.fierce. fierce counter = counters cr.normals like cr.lk or cr.RH.