1st When was bug ever weak to ice?
2nd Kabutop probably tanks flare blitz better then Feraligatr have a quad resistence to fire being a water/rock type but it still have to worry about the predicted Hidden Power Grass from Entei. If you're talking about general bulk then yes Feraligatr has better bulk and typing to take hits.
As for Feraligatr > Kabutops, I say it's a toss up, depends what you want, but once Sheer Force Feraligatr is out I'd say Feraligatr > Kabutops. I can't wait for sheer force boosted waterfall, Ice punch and Crunch.