Couple tangents in mind I'll try to keep short:
For one, I'm not sure why people bring up the weight difference so much when discussing Pichu vs Pikachu. Pichu has a weight value of 62 compared to Pika's 79, which I suppose is a big difference, being the equivalent of going from Lucina's 90 to Ike's 107. However, Pikachu is still tied for being the 6th lightest character in the game (for reference
have 79,
has 78,
have 77,
have 75,
has 68 and the aforementioned 62 of
). Pikachu will live longer than Pichu but won't exactly live long in most circumstances. Though to be fair, movement specs play a lot in survivability as well, being able to more quickly avoid attacks and Pikachu isn't too much bigger than Pichu, making him still a difficult target to hit. Pikachu has a better run speed, the same air acceleration and initial dash speed, worse top air speed and while his fall speed is worse, they have nearly identical fast fall speeds. Pikachu also doesn't have the self damage so perhaps it is significant. Just comes off as a bit odd to me that weight gets brought up a lot when regarding the rats when Pikachu isn't exactly heavy.
Speaking of weight, while it hasn't been brought up recently, a similar situation happens with Ridley where people like to group him with the super heavies but then also mention how he's 'much' lighter. He's still tied for being the 8th heaviest character in the game (again for reference
at 135,
at 133,
at 127,
at 118,
at 116,
at 112,
at 108 and
all at 107). Ridley is only 9 units off from the lightest super heavy in the game. He has the hurtbox size of one (and recovery for that matter...) but he's not too much lighter than them.
As for the clone talk, there's varying degrees of clones and a semi-clone is still a type of clone. Characters like Luigi, Falco, Lucas, Ganondorf, Roy and Isabelle are all often considered semi clones because their moveset has a base in another characters moveset. They're obviously not as similar as the echoes but they aren't completely original either. Not a big deal for a character to be called a semi-clone. It's just an acknowledgement of where the moveset branches off from.
As for the patch talk with echoes, we've already had Ryu and Ken affected differently by a patch in this game and back in Smash 4 we had Dark Pit and Pit get some separate changes in patches like Pit getting a bigger hitbox on his rapid jab finisher and Dark Pit getting a stronger side special while Pit's stayed the same. It's entirely possible for Lucina to get nerfed without Marth being touched or for Marth to get buffed without Lucina getting it. Oddly enough, the 2.0.0 patch notes mention changes that Samus got that Dark Samus didn't and yet the two got the exact same changes. Someone simply forgot to list one of the changes for Dark Samus.
Last thing I'd like to comment on is the Zelda post, specifically in regards to priority. Unless I'm mistaken, I don't believe any of Zelda's grounded normals have transcendent priority or trample. Due to this, the priority of her moves is purely based on their damage values with jab, fsmash and usmash being multihits which have comparatively low damage until the final hits. Jab does 2.5% before the rapid jab and then does 0.2% until the 3% finisher, Fsmash does 1% until the admittedly powerful 13% finisher. Usmash does 2% then 0.8% and ends with 5%. Two of her specials are projectiles and therefore not generally used for clanking purposes. Not sure if grounded Nayru's Love or Farore's Wind can clank though the former also has intangibility during the hitbox I believe (it did during Smash 4 anyway after patches) and it'd be rare for Farore's Wind to clank if it even can due to it being a teleport. The more noteworthy moves for clanking or beating out moves are ftilt doing 12% with the magic and 10% with the arm, dash attack doing 12% with the sweetspot, followed by the less impressive 9% sourspot and the 6% late hit and then dsmash doing 12% at the front and 10% at the back. Most aerials can't clank with anything but projectiles although there are some exceptions like the projectile ones such as G&W's fair and Mega Man's pellets and then for whatever reason in Smash 4, Olimar's Pikmin aerials could clank with non-projectiles too. A reminder that a move flat out beats another if it does 9% or more so Zelda's powerful grounded moves can beat out weaker moves like most jabs and some tilts and dash attacks depending on the character.