One can sip wine all day and fulfill what this sefer suggests.
Not really. He holds you’re supposed to get quite drunk, and that won’t do it.
He definitely says that unless you know that you won’t do an aveirah in your drunkenness, you shouldn’t get to that point.
I also agree that anything more than “simcha” is not required, or appropriate, at night. Not drunkenness.
But, let’s be honest. Go through all of his teshuvos there, you’ll see that the ikar mitzvah is to get very drunk.