INT Affect Gravity?

NVM

You can actually, a few updates back he added a negative checkbox. As a side note for testing purposes, one could use ulhuadshi to suck your stats dry and cast on some normal mobs. Such a significant difference in stats should be able to show you if there is a low cap or not.
Random chance is all I can assume. I've never seen significant tests on bind break resistance. Not saying it isn't possible but a static rate per damaging action is still capable of producing those results.

I think the random nature of bind coupled with the higher than normal resist chance due to a high level mob with high stats could likely explain people thinking they gain resistance but my solo experience has loosly implied that there is something going on there even with bind just not as pronounced and obvious as gravity is.

To add to this, these spells have semi-random duration. This may not be exactly how it works but you can see kinda how they may have gone about the process. The numbers in this are totally fake and not based on any testing at all:

Base duration for bind might be say 15 seconds. A random number between 0 and 30 is generated and added to it. So you might have a 15 second bind or a 45 second one. If the spell had a part-resist then that is applied to the resulting duration so a half resist of a 15 second bind might leave you with a 7 second bind while the next resist level would have a 3 second and so on until it literally wears of as it lands. On the other hand a 45 second bind(the "max" duration Hevans speaks of) half resisting would be a 22 second duration.

Perhaps that will help some people out why bind and gravity can be so random.