Jinbei's moves:
1st one is his iconic Judo move, Fishman Jujutsu Shoulder Throw. It is a technique with various prefixes, sometimes depends on the substance he uses(Like Red Tea Shoulder Throw, or Sea Current Shoulder Throw), but he's also done it directly on a person(Whirlpool Shoulder Throw on Big Mom). This one is called "Tide Attracting Shoulder Throw", the "Tide Attracting" part probably refers to the effect of the motion, like the "Whirlpool" prefix.
2nd one is the grip technique Hody used to break the building, likely used by Jinbei this time in a "bite competition" against one of Who's Who's teeth techniques.
3rd one is his new Ougi, means "Demon Tile True Punch", likely the Ougi version of the other "Tile True Punch" in Fishman Karate.
Who's Who's moves:
Moon Walk(Sky Walk), not Monthly, sorry I laughed here.
Fang Flash Bite is likely a technique used by Who's Who to have a bite competition with Jinbei's "Rough Shark".
Finger Gun Spot is a move like Gatling version of Finger Gun, it was used by Rob Lucci before, the "Spot" refers to the wound mark it would leave on the opponent, which would resemble the spots on a Leopard I think, as a Neko Neko no mi user, Who's Who is proficient at Finger Gun, just like Rob Lucci.
Last question, the correct translation should be "I think he's been defeated because it was an Ougi(Secret Technique)."