[Interstellar] The water planet

I just watched Interstellar, and, decision-wise, the one thing that still remains implausible to me is their decision to even consider the water planet as a viable option:

1. Wouldn't the black hole's pull on the planet only increase, making the planet increasingly unstable until it was eventually consumed by it?

2. The time dilation itself should have ruled it out. Even disregarding the fact they forgot that the original scientist would have subjectively had very little time to thoroughly explore and record her findings, it would mean that there would be little-to-no prep time for the team to make the planet ready for colonization for Plan A.

It seems that an overall lack of comprehensive data, especially when compared with the other two options, along with the site's poor suitability for establishing the equipment for a colony, should have caused the scientists to choose the other two planets instead.