Again, I fail to see the issue with this. It sounds cute and entertaining. I'm sure he'll get more serious as the series goes on, just right now this seems like a good start.
The kid with the construction deck and the guy with the tomato deck also instantly developed a crush on Kotori. Even though this is a villain, I don't expect this to be handled significantly different, especially when Alit is suppose to duel Yuma not because of his Number cards, but for Kotori's heart with Yuma, most likely, being oblivious as to what is really going on.
We haven't seen the episode so I think it's a tad presumptuous to assume they won't be a threat. Alit-sama has a crush on her, which can be called 'love at first sight' and I don't think one person's judge of character can really show the rest. Misael sounds serious and menacing, as does Durbe. Gilag and Alit-sama seem to be a tad more 'goofy' so to speak, but I don't think this messes up their character. I assume they'll have more development plot-wise later anyway.
So, from the sound of it, it's more along the lines of Judai dueling that tennis guy in GX for Asuka, except with villain as opposed to a boring one-shot character. Still, the fact that Alit instantly develops a crush on Kotori and duels for her heart continues to make me wonder how much of a threat these Barian villains are and if I'm suppose to take them seriously at this point.