I do have trouble believing the flood story as the bible presents it as a worldwide event at once. The scientific finds don't seem to back it up to a lay person ,it is similar to the evidence for the exodus with moses , where is the evidence.
Clams being shut and fish swallowing fish ,to me , only show that they died quickly due to a local event that may not have been a world wide flood. The fact that some creatures have not changed much in what scientists say are tens of millions of years just says to me that the environment for them has not changed enough for them to adapt.
As to the length of creative days ,well if you are going to believe stories in the bible ,then it would of course be possible for god to do this in such a short time because it written like fables and stories of gods like the greeks believed in. That's why when I left the JWs I broadened my outlook of religion and studied up on how religions formed etc
It seems incredible now that I bought into this belief of religion and how ignorant I was to believe what the Watchtower told me ,and other beliefs well ,are so varied ,it simply shows how man made religion is ,it seems to me it was evolved as a response to living in this world and coping and driven by power hungry people and ignorance.
As has been noted here the WTS could probably say satan put the fossil record this way to decieve future generations, they are not alone and all we have is written down ,by men ,words that say such and such in all of the denominations of christianity ,24 hour periods or 7000 year periods or millions of year periods which is it?
It seems to me only science is moving forward to find a truth about the past and actually prove something by evidence that harmonises not written words that have formed by corrupted men's thinking and greed .