I'm wondering if the Ken combo and/or European Ken Combo can be done in beta... How does one even reverse up-b actually?

The EU ken combo can't really, because a reverse upb in SSF2 is reversed before frame 1, whereas the main games keep you faced forward very briefly before reversing. You'd have to be inside your opponent to get the reverse hitbox.

I'll add that the sweetspot hitbox is still doable if you just don't reverse and will kill, you just have to only use if you can get back.

I'm the sort of person who has "phases" with a character and will keep attempting to do a certain combo until I get it (for example with falcon, any combo starter/lead -> RAR bair -> reverse knee still haven't done it yet sigh), and with Marth, it's the PAL ken combo trying to use the reverse aerial dolphin slash. But out of all my attempts, it never kills since it's really easy to DI the sweet spot and survive :/
Hope it's stronger in beta since I find reverse up-b super swag in melee and ssf2

When you try to do reverse dolphin slash and you hit with it in ssf2 (as in, you are close enough that your back hits them when they were just in front of you), you'll never get the tipper because the tipper on upb is all the way in front of Marth, not close into him. When it happens in Melee it has everything to do with hitbox interpolation or something like that, the tipper hitbox stretches the most while Marth turns around (which makes it huge) and thus makes it easier to land.

Screw Marth, SMASHVILLE FTW

LOL.

There are indicators to show that you hit the sweet spot, because the character who has been hit, tell me if i'm seeing things, stays frozen-ish for like 10 frames or so, idk. There is a huge knockback distance change, lemme tell you between the sour and sweet spots at much higher percent (like 70). However, sweet spotting makes your opponent go a lot more horizontal than vertical, which is a bad thing or a good thing depending on the situation. To recover, better to sweet spot, to combo, sour spot. As for the ken combo, I don't know about the pal version but for me personally I can't really change whether I spike or not (I'm not a pro n all) but dolphin blade's sweet spot is still hard for me to hit, even on the ground. The Pal KC is just too hard to really successfully pull off 100%, and i really think it's more worth to try for the meteor smash.

But yeah, here's hopeful for a small buff maybe. to the knockback.

Also for some reason WHY DOES UP SMASH HIT ON THE GROUND??????

Wow I just realized how powerful marth's s-smash is, it kills naruto from the starting point at 32% when sweet spotted.

Oh yeah dude, Marth is my favorite character.

This might be a stupid question to ask, but will a priority 2 move beat a priority 1 move, or the other way around?

This is with a CPU right? They always DI reverse dolphin slash really poorly so it makes it seem great but in reality, if you hold in when DIing, you the angle is really easy to survive even at high-ish percent. This sucks when you try to combo a human into reverse up b, the opponent is usually at the point off stage where they'll hold their DI in no matter what so they almost die but not quite. Yeah at this point, you get them in a good edge guard situation but I'd like that extra 'oomph' so they hit the blastzone :]
Ah and like you said, the freeze frames in sweet spot up-b make the move feel great

Please tell meh about priority
I got no idea whether what beats what

Priority is weird. Just don't worry about it. Most of what we think of as priority is really disjointedness anyhow.

Soo

If Beta is actually coming up very soon, any nerfs/buffs or changes you guys would like to see head Marth's way?