I think you just don't know the matchup, Bking.
I can tell you about Samus v Pikachu because my friend plays him and I have a lot of experience with that matchup. You need to jolt a lot, yes. Samus will camp you pretty hard, but if she's on stage, you need to get inside her to get some combos in. If she is planking, don't challenge her on the ledge. Just go to the other side of the stage and jolt her. If you go near the ledge, she will probably jump up and do a retreating fair to poke through your shield. Even if the first one doesn't work, she will just do another one. This method for her is pretty safe. She can also drop back and missile or zair from the ledge, which is why you should just back off and let her have the darn thing. You can try to send thunder at the ledge, but that won't always work. Samus is a true annoyance to play against, but she's still susceptible to most of Pikachu's combos.
If Samus is short hopping a lot and using missiles or something, she is probably trying to bait you to come over and get hit by a few of her dairs into the ground. Don't fall for it. Missiles are actually usually used for baiting. I don't see them as good for much else. She might also be baiting you to leave yourself open for a fully charged shot. Like, if you shield too many of the missiles, your shield will be low for the charged shot. Don't forget that you can just ftilt or jump around missiles if you need to.
Oh yeah, she will also up B out of shield if she sees you miss something like a grab up close. It's like her gtfo move. Think of it kind of the same way you think of dolphin slash for Marth.
Nice kill at the end of the first match btw.