IMHO - the rat bait is very cool. I like the detail you added with the look of the hairs! As to your swimming issues.
I would create a larger gap, between the two pieces, and make the V in the back section wider. Think of a really well rounded, baby got back butt!
As far as the lip goes......Keep the lip barely angled towards the front, and you may want to try the line tie in center of lip!
Just my observations after looking at your pictures!