I have my Elite Ewok Spare Marines patrol around my facilities to gain XP. They receive the same amount as they gain from travelling in your party. They will patrol the route you give them in a circuit until ordered otherwise.
In the case of patrolling I am unsure if they stop to attack foes or simply alert you, but the guard command is considered as an "attack move", they will attack any enemies in range en-route and at the final destination.
Edited By: Phillip Bromley on Year 12 Day 173 18:24
As long as you're in the same city, you can cancel orders and issue new ones. They're are called remote squads, after all. However, you can't issue new orders when you're not in the same city, or across the galaxy. I don't know if you can cancel them at a distance though.
Was just thinking of setting up mah troops to run around in circles until they got to lvl 3 and then telling them to take a break while ah was off traveling the galaxy, but as long as they get the same amount of exp on their own as they would tailing me, ah can set up the extras to follow while working with ship crew/family members (or maybe just sit in the corner and order the lot to do a dozen laps while hairy Teniel serves me chilled beverages :D)
I doubt they'll get much past level five in a reasonable amount of time. I don't plan on leveling my Elite Ewok Space Marines any higher than that, since it's more worthwhile to just train another squad to level five in the same time it'd take that squad to get to level six.