On Geonosis theres the area where you first face the Geo Elites, before you get into the droid foundries. Then the canyons and the end with the timed level on the Core ship.
For the RAS, I usually have some trouble with the trandos, I'm fighting solo and usually rely on the vibro-blade and snip attachment. But when I find shotgun, things became much easier. Things get hairier for me when it comes to the hangers.
And finally on Kashykk, the magnaguards can be a hassle and the bridge is one big pain. Also I tend to struggle when fighting the Geonosians at the very end of the game.
Remember the breeze across your face
Remember the swaying sleeves in the wind
Remember the grains of sand beneath your feet
between your toes
Remember the freedom in the never ending waves
Remember I'll be at the beach.
Jedi Academy - Renaissance