After reading over your post, I'll admit that my earlier post here does indeed suck, and that I somehow did not know my own main as much as I thought I did, prior to this topic, despite me sounding like I did know. I probably know DH more than I know Jr as of this point in time, due to the amount of data, attention, & players he gets in comparison to Jr, which is a real shame.
1. USmash is definitely Jr's most reliable Smash attack, especially OoS. I spoke of FSmash for its KO strength being above USmash. However, FSmash is our least reliable Smash, due to it being DI-able, sometimes not properly connecting, and being slower to come out than USmash or even DSmash. Speaking of DSmash, despite its long recovery frames, it's more reliable & quicker to reach the KO hit than FSmash. Of course, USmash trumps all of his Smashes.
2. Jr's UAir is good enough to protect his squishy head? I genuinely thought the majority of the cast could heavily disrespect it, including Lucario. I also thought that Jr's anti-airing abilities were terrible enough that staying above him was a safe place to be to score headshots (reminds me of 3S!Chun-Li when Parries aren't used...), which folks like Jigglypuff, Kirby, and another Jr could definitely take advantage of. It's nice to read that Side B JC mixups can tempt folks to spend 2nd+ jumps. I was at least aware of how hard it is to land Lucario's DAir, despite it being his fastest aerial and giving him slight hang time, but . None of Lucario's Counters are good against Jr's Side B, especially when JC'd? I was wondering why I found Counter users in general to be among Jr's easier opponents, aside from said Counters denying me UAir & Up B --> A (Hammer) sharking attempts....
3. Really? I coulda sworn that Jr gains SOMETHING worthwhile from Customs, however little it may be. 3111 and 3113 are definitely decent sets, and I'm glad they're on the EVO Setlist. The main reason I like Meteor Ejection as much as I do is for its super armor to help defend against deep edgeguarders, most notably Yoshi, ROB, and ZSS. I don't actively try to spike with it until I've spent all my jumps, including the Side B JC, trying to deeply edgeguard folks. Piercing Cannon is definitely the worst of the 3 Cannons. I normally don't use it, and the only MU I would really want to use it in is against Rosalina, just as a distant tool for KO-ing Luma, and even there, I wouldn't want to recklessly throw it out against a Rosaluma running 2311 or 2313. I'm definitely a fan of Air Cannon, and I'd certainly recommend that over default Cannonball for quite a number of MUs, most notably the likes of Yoshi, Ness, & Falcon. For this MU, however, I'm not sure if Air Cannon's worth running. Sure it's the fastest of the 3 Cannons, and it can catch Lucario when he's in freefall after Up B-ing, but even at 0%, Aura Spheres pass through it and can hit you. If it IS worth running against him, I'd like to know why.
Of the official EVO sets, I'd personally run 1123 against Lucario, since neither 2123 or 3123 are available (I'm ok with 2123 not being there, but not so much 3123), and default Cannonball can at least handle Aura Spheres under 100% when Big Mecha's already out.
4. Non-Omega Lylat Cruise actually sucks for Jr? Whoever I've heard claim that Lylat Cruise was good for Jr must not have known what he was talking about. It seemed decent when I was running Impatient Mechas, since it seemed to be the most reliably functioning Mecha on that stage. Aside from that, I do agree that Lylat sucks for Jrs that run default and even Big Mechas, considering how hard it is for them to stay on the stage. That Side 1 & 2 are slowed down when going uphill... How have I not noticed that, despite playing Smash Run and Side B-ing up 'n down hills? Then again, Grounding Dash is the Side B I've ran the most on that stage thus far, which has the fastest movement speed (once you get past its long grab-able startup, which does have super armor. The grab-able part is another reason why I'm not recommending Grounding Dash in this MU, which Lucario's Side 2 can definitely punish) to counteract the slopes. I also agree that Jrs running Side 1 or 2 hate Lylat for those slowdowns. The full set that I've ran there the most is 3322, and I've come to that combination while trying to figure out what the ideal stage & custom setup would be to fight custom Yoshi. That must be why I made the claim that I did. Taking 2123 or even 1123 to Lylat is definitely a bad idea with all that intel in mind, as would any other set, aside from maybe 3312.
I was aware that Jr was at least decent on FD/non-walled Omegas. I didn't expect FD to be that good of a stage for Jr like it is for DH that banning it would be a great idea for the opponent, let alone Lucario players. I understand Delfino being worse than decent for Jr, due to his lack of super-safe upward KO moves, headshots being very devastating to him there, and default Mechas being unable to patrol much of the stage when the detours show up, but Castle Siege also being a bad stage for Jr? Aside from Mecha throwing & default Cannonballs being blocked off by the stone figures in the 1st transformation, said transformation and transitions being terrible for default Mechas in terms of staying on the stage, and the threat of suddenly being KO'd by the stage itself during the transitions to the 2nd & beginning transformations, I thought it was a decent stage for him. Turns out that's not the case.
5. I did that? Whoops. That was indeed quite dumb of me to do. It reeks of silly fanboyism, and thus I shall stop it.
Thank you for constructively critiquing my above post. I actually needed that wake-up call. I'm already expecting my Jr to substantially improve now because of your post.