I know that if characters role play toward their motivation they should get 5xp for it but generally are there any other guidelines for awarding xp regarding combat or story objectives?
The amount depends on how fast you want the PC's to advance, a slower progression means 10-15 EXP for a roughly 4 to 5 hours long session. While a moderate progression means about 20 EXP per session, meaning that they will buy at least one talent at the end of each session. And lastly, a faster progression is anything from 25 and up, but you should be ready for some quick powerleveling on their part.
But you have the freedom to set that value yourself, some adventures will reward EXP if the PC's complete certain objetives, while leaving room for the GM to use his creativity to complement that aswell.
Another way to handle it that iv seen on the forums (and i like, personally) is to award roughly 5 EXP per hour of game session, and adjust that to your liking. Normally that means anything from 20 EXP to about 50 EXP.
Combat hardly gives any experience, because the enemies should provide a challenge, but fighting them shouldn't be the objective of the game.
The GM should award experience points after every session. The amount awarded is typically 10 to 20 XP per character for a session of two or three major encounters and a handful of minor ones. An additional 5 XP bonus may be granted for reaching key milestones or completing story arcs. Playing to a character's Motivation also grants 5 XP per session at the GM's option. The GM may consider awarding an extra point or two of XP for exceptional roleplaying or highly clever thinking. Published adventures may recommend XP awards. - p. 301 Edge of the Empire