I do think Villarreal went into this tie quite cocky and even more so after the first leg.
I don't think the players were, but their manager set the team up to keep a clean sheet at Anfield and did not change his plans after Liverpool scored so early. That is very cocky. I think his players were extremely frustrated with how things were going and I don't think Soldado believed in the way they approached the game. The way Villarreal's forwards were dropping so deep played into Klopp's hands. It's easier for his teams to pile on pressure when the opponent can't get the ball past the midfield lines, and it's easier when defenders have to play lower percentage passes past the midfield up to those forwards. Villarreal deserved to lose because their tactics weren't appropriate for the situation, those were tactics you use in the first leg.
The Final is an even game as has already been said. The issue for Liverpool is that Toure and Lovren can be exposed against a smaller, more quick forward like Gameiro. On the other side of the coin for Sevilla, it is alarming that they were so porous defensively against a team like Shakhtar who has less offensive talent than Liverpool these days. Could be a wide open game in two weeks. Liverpool will need Milner and Can to have similar impacts as they did today, and it will be interesting to see what Origi can offer from the bench given he should be back by then. I think Liverpool will be far more cautious given that Sevilla is not going to approach the game in a similar way to Villarreal. Sevilla will also be more intelligent and put their best attacker (Konoplyanka) on the same side Moreno's on, not the side Clyne is on. Suarez switched to the other side late in the game today but that was too late.
Klopp does have an interesting job fixing what's wrong with Liverpool, and most of those things could actually be seen in this tie. Moreno tends to run much too far forward and forgets his duty in going backward, he also needs to take on defenders more when he's that far up the pitch. Lallana isn't really good enough despite how hard he runs and even though he scored a goal. He could have played Sturridge into great positions a few times and misplaced his passes. Goalkeeping's another. That being said, they're all one game away from being legends and it's a little difficult to not be emotional right now. This could ultimately be the most rewarding season in a decade when all's said and done.