Hello,
1. General Remark about Kryptonians
I am a big Young Justice (Comic-Series) Fan, especially Conner,Bart,Tim and Cassie.
I like Conner, but I dont like the portrayal of the Kryptonians in the DC Universum.
I mean we have many Kryptonians,but they all have the same power sets: Jor El, Kal El, Kon El,Kara Zor El,Jon El,Zod...
I liked much more the Dragon Ball Idea: In Dragon Ball we also have many Sayajins but they have different powers, even their powers are also based on an unique source: Ki.
This would have been a cool Idea also for the DC Kryptonians whose power source is the Yellow or Blue Sun.
I mean basic Kryptonian Powers for every Kryptonian (Super-Strenght,Flying,Kryptonian Senses,Invulnerability....) BUT!! instead of Heat Vision and Super/Freeze-Breathe just developing other variations of solar powered long range attacks.
We have already seen that Kryptonians could use also other body parts: Kara Zor El,Clark and Jon showed this while doing the Solar Flare.
OR you could also change and use Superwoman (Lana Lang) who had Electric Powers like the Blue Electric Superman.
For Conner its simple: Kryptonian Powers, but replace Freeze Breathe and Super-Breathe with TTK (because he can control whatever he touches so it would be simple for him to create wind etc.), if he has to wield something he can also use TTK
and instead of Heat Vision as long range attack he could use something like the Galick Canon of Vegeta.
For Jonathan, Kryptonian Powers, but use the Superwoman Concept on him. So Kryptonian Powers and his Heat Vision,Super Breathe and Freeze Breathe replaced by electric attacks and control of the electrons around him. So more like her https://dc.fandom.com/wiki/Lana_Lang_(Prime_Earth)
Its also interesting: Dragonball has Son Goku, Son Gohan and Son Goten
DC has Kal El, Kon El and Jonathan
To bad that Jonathan is older now, because with young Jonathan it would fit perfectly.
Another Idea for Conner which I like would be Kryptonian Powers, but replace Freeze Breathe,Super Breath with the Telekinesis of NEW52 Superboy and also his Telepathy..
So you would have 3 Kryptonians with Invulnerability,Flying....like every Kryptonian (Strenght Level based on their age) and individual powers, which makes them different, but without making one weaker or stronger, just different.
2. Conners Costume
I personally like it that they get back to a Version of the old costume...I personally didnt like the TT Costume, BUT I would like to see Conner in a mix of TT and YJ Costume..Like Arnold Schwarzenegger in Terminator....Use the black/red Shirt or the Fleischer Shirt of NEW52 Superman with Jeans,Boots,Leather Jacket and Pilot Sunglasses...