Temperature itself does not affect the speed of light - remember that space is freezing cold, and light moves through it just fine. So warmer temperatures don't do anything with time.
If earth suddenly gained a bunch of mass, that would change things up as gravity would increase. However, we wouldn't really notice, as everything would speed up more or less the same. We'd have to compare ourselves to someone in a system where time moves differently in order to notice.
Think about what it means for "time to move faster". If you're within the faster timestream, you may not even notice, unless you ascribe to one of the more interesting metaphysics which theorize that consciousness can exist outside of time. But if you're within a different timestream, you may notice the affect timestream speed up or slow down relative to your own timestream.
Now, I've read your potential reasons why temperature may affect the passage of time. As to E=mc², the energy is not increasing, but more potential chemical energy is being turned into ambient heat, eg. by burning fossil fuels. Super simplified, ofc. but it's not a case of energy being added to a closed system.
Yes, the increased amount of water would slow down the rotation. Couldn't it also slow down the planet's forward motion? Then the planet steps down to a lower circle around the sun, and then we get hotter. And time goes slower because of increased gravitation of the sun.