Standing back from the edge you should be able to take a step or two and then jump to reach the far platform. You can jump and then move the left stick forward, but you will not get enough distance that way.
If you can not get a feel for when to jump with a little practice, try pointing the camera down rather than towards the platform you are trying to reach.
The possible problem toggling combat mode is if you jump and then in mid-air press down on the left stick. I never had a problem with this for platforms, but near the start of the game accidentally pressed the stick down a few times when trying to run/jump/dodge during hectic fights. I adjusted my strategy a bit, and got used to the combat, and no longer had an issue.
