Pocky & Rocky / Kiki Kaikai: Nazo no Kuro Manto

You can add loop points, yes. They're specified in samples. The WAV2MSU command would be...

wav2msu track.wav -l samplevalue

You can usually find some way to loop tracks seamlessly even if they have a distinctive ending.

of course, with the files you're creating the remixes from, you could probably easily design a loop point. if you need assistance figuring out values to loop to etc feel free to post up in here and i'll do my best. i did some tracks like a year ago just to see how it was done