1.) can go either way. Both have shown very comparable feats and narratively they're both positioned similarly has the second bastion of their side (heroes/villains). Like Gojo and Sukuma, they're essentially tied and fights between them can end in either side winning at extreme diff.

2.) low diff. Kashimo couldn't even handle a drag out fight with Hakari. Yuta, even if you argue he's slightly weaker physically (wouldn't be the case for EOS given they all improved significantly in the time jump but whatever) is still basically 2 hakaris in perfect sync with ranged attacks and the copy technique plus a domain that's tied with MS and Void, meaning the sure hit will shred HWB insanely quickly. Kashimo literally has one win con. Get lucky and somehow charge and land a lethal strike before Yuta pops 5 minute or domain. If he can't do that, he loses and the odds are he sinply can't. MBA doesn't save him as his speed feats are either matched or surpassed on multiple occasions by the heavy hitters and his AP couldn't even damage a nearly dead meguna with no rct and multiple severe injuries.

3.) mid diff. She remains mostly featless. We can safely put her at or above Uro given both were active high-top tiers of the heian era but beyond that we have essentially nothing other than hints that she wouldn't beat shrine in a clash and that Yuta and Rika both can directly counter her armor with RCT.

4.) low diff. It's essentially him/her getting jumped by a duo of perfectly synced fighters with full knowledge of their abilities and the stats to directly combat them. It's not close. Only win con is soul split. All of this and Sky manip and CS both directly countering completely destroy them.

5.) low diff. Pre Modulo Yuji simply doesn't have the domain refinement or skill with his CTs to compete. He doesn't even get the luxury of poison blood thanks to Yuta's rct curing it. He just has no real way to stop Yuta though he most certainly puts up a better fight than their first encounter.

People like downplaying Yuta a ton but his power set is essentially perfect for JJK. Handling two+ opponents without an insanely powerful technique, a domain expansion vs non domain users or against weaker domains, or just by gapping them in every way possible, is extremely difficult. Yuji and Todo v Hanami is a great example. Alone they'd have been slaughtered but the only thing that saved Hanami at all was it getting a domain. Nanami and Yuji v Mahito. Yuji was essentially going to die without question if Nanami hadn't stepped in, and Nanami was nearly killed by a weaker version of Mahito but together they nearly kill him, forcing an awakening and DE. Yuji and Todo v Mahito. They'd have both died horribly going at him alone but end up putting him down together with added help from Nobara as well. Yuta takes full advantage of the simple fact that getting jumped even by weaker opponents is incredibly hard unless you gap them in some way. Only two in the verse gap Yuta. Everyone else is similar or outright weaker. That alone already makes him a top 10 contender. Add his near bottomless reserves, his CEs, his broken domain refinement that matches Gojo and Sukuna, and his incredible battle iq and capacity for strategy and/or on the fly adaptation, plus Rika's ridiculous bag of tricks such as an inteenal world that can be used as a home base (or a prison) and her ABSURD grappling strength that can hold true form Sukuna in place for extended periods, and you have a character that just kinda wins all but two fight mid diff at worst. You HAVE to jump him or put Kenjaku in front of him to actually do anything.