Unfortunately, you won't be able to get Magnezone until after you beat Noel. That said, Magneton should still be useful against Swellow, but that Staraptor is packing Close Combat, so make sure your Magneton has Sturdy and is at full health. Also, if your Magneton knows Flash Cannon, that should help against Clefable; again, make sure it's at full HP so you don't get completely KO'd without at least getting one hit in.
I'd like to say that Lanturn can take care of the birds, but Lanturn is really frail, and it doesn't hit all that hard either; you might be better off dropping it for Magneton.
We'll let you know when we find out lol; we're probably not gonna get Fly for a while. The backtracking will get a little better after you beat Noel, but only slightly
Here ya go
We don't have those either unfortunately. We're stuck with Berry Ice Cream and the few Hyper Potions that we find on the ground.
Here's a sticker list though
Can you take a screenshot of this? I'm a little confused, but I may be able to help with a visual aid.