GaW approaching Snake is kinda hard. Tbh i just hang around and wait for a mistake because that saves me trouble but if you really need to approach you will probably need to mindgame somehow; straight up Bair should never work, although if Sheild is small or he doesn't have a good setup, you may be able to poke him with the tip of Bair. Perhaps empty shorthops and if snake uses an attack which misses you then maybe you can Bair him or Nair. Dair can work if you bait the Utilt and slowfall, then continue before he can do anything else. It's not easy sorry
I honestly don't think rolling is ever the best option with GaW. Just don't roll lol. It's already considered pretty bad, because you can't directly control your movement and spacing so you become easier to read by limiting yourself, and also GaWs roll is probably the slowest and has very few frames on invulnerability. You can run faster then the roll and thats 100% safer because spotdodge has more invulnerability then roll to afaik. Don't roll, please.
I honestly don't think rolling is ever the best option with GaW. Just don't roll lol. It's already considered pretty bad, because you can't directly control your movement and spacing so you become easier to read by limiting yourself, and also GaWs roll is probably the slowest and has very few frames on invulnerability. You can run faster then the roll and thats 100% safer because spotdodge has more invulnerability then roll to afaik. Don't roll, please.