If you're a fan of 60s lounge singers, this episode was meant for you, and I sincerely hope you enjoy it. But this episode wasn't written to suit my tastes.
On occasion, I've listened to that genre of music. I was given tickets once to a concert for a big band singer. Basically an hour and a half performance similar to Vic Fontaine's. I really enjoyed it.
But that's what I went to the concert expecting to see. I don't tune into any TV show, much less a scifi show, to see the performances of a lounge singer. I completely agree with you. It was too much.
Watching the episodes back to back, even the single numbers in the future episodes start to wear thin. I don't dislike the Vic character, but I can't bring myself to LIKE him. I enjoyed him in the second half of Nog's rehabilitation episode and would have liked him in Badda-Bing, Badda-Bang if that had been a season 1-3 episode. James Darren has a great voice and is a good actor. But Vic seems a bit too much like a Marty Stu to me. He was introduced out of nowhere, immediately everybody adores him, and he almost always knows better than the rest of the established characters. I think the character Vic detracted more than he brought to the show.
About the romcom aspect of the story. As a female, I've seen plenty of romcoms. This was bottom of the barrel. The majority of it felt either contrived or slightly creepy. Which is a shame, because the few good romantic comedy movies have a bit of angst and provide enough history between the characters to to make the plot feel genuine. Kira and Odo have enough history and depth to their relationship that it shouldn't have felt corny and didn't need a matchmaker we've never seen or heard of before to come solve all their relationship woes.