Any benefit in using Razz Berry and Great Ball at same time? Any harm?
Solution 1:
Yes they are additive if used at the same time.
There is no data on if using a Pokeball and missing causes them to run away faster after a failed catch.
More often than not, the reason for the run away is just the higher the cp and more difficult a capture is, the higher chance of running away seems to be.
Solution 2:
Yes, the effects are additive. This can be seen by tapping and holding on a Pokéball to see the color after throwing a razz berry, and then releasing it and switching to a great ball and doing the same thing. You will be able to see the difference in color of the ring change color (provided it wasn't green to start with).
source- personal experience