Wow, you know how to ask some LOADED questions don't you? LOL
At the risk of going down in flames here, I'll tell you what it sounds like to me:
First, how deep is the dropped keel? You stated that it looks pretty healthy to you. 5/8" is getting pretty healthy, and should be good to the speeds you are talking. (let me interject here that I'm not at all familiar with a liberator either)
It sounds like the set-up is way wrong, and you are not getting enough speed or lift to get the boat to fly. Was anything done to the shoe or rideplate after adding the keel?
I don't really see how the dropped keel could be acting like a hook.
The thing that comes to mind is that maybe the shoe is way too high now.
Man, without seeing the boat, you are almost asking the impossible.
I'd try calling Duane, Jack, or another to have someone look at the boat.
Sorry, didn't help much, but there are just too many variables to diagnose it over the internet.
Ken F