Short hop bacon is very useful, but as the previous poster mentioned you can't just mash b to use it. The timing is pretty simple, but be careful not to do a grounded bacon like the way a Falco might accidentally do a standing laser, as it leaves you pretty vulnerable. Similar to Falco, actually, GW seems to have his own kind of pillaring combos. Learning to use his up-b to continue combos is important, as you can still act out of his up-b. Something like: up tilt, up-b, down air, down tilt, up-b, neutral air is one example of his "pillaring" that is easy to do on larger characters or if the opponent DIs poorly. His up air is also amazing at juggling. The bucket is great against projectile users, and it's especially great in PM because you can release it by hitting down b twice quickly even when you haven't absorbed 3 projectiles. It can also be used to stall in the air.
I personally don't use GW side b at all. While I won't tell you to not use it - you can do whatever you want, and it can be used well- here's my reasoning: It's mostly random. Yes, you can tell if it is even or odd by the dots, but you could swing and get a lucky 9, or swing and get a very unlucky 1. This isn't even high risk, high reward, it's just relying on rng and I don't like to do that at all. It's fine to use it, just be careful not to leave yourself too open if you're in a dangerous position near the edge or at kill percent.
The main thing to remember about GW is that he's a glass canon. He can dish out incredible damage, but he's very light and his defensive options are poor. Thankfully his shield functions properly unlike in melee, but his roll is very slow and he has trouble with other out of shield options. If there's any aerial to use OoS, I'd say a short hop down air or possibly back air if the opponent is behind you. But his best OoS option is probably up-b. It hits on frame 1, I believe, and since you can act out of it you aren't left very vulnerable.
If you can't Wavedash or L-Cancel consistently yet, I would recommend practicing those before you learn the more specific GW techniques. GW may not be a spacie, but he actually requires a decent amount of tech skill to be successful with - more than one might think. Because his aerials have long landing lag (especially forward air), L-Cancelling is an absolute must, unlike some other characters (no offense meant) where you can do just fine without L-Cancelling. His Wavedash is also quite good, and is another necessary for quick movement.
I'm no GW expert, but I've been playing him in PM for 2 years and this is just a bit of what I've learned so far. And there's still so much more to experience!