RotE first run as officer

You should probably aim for about 9 stars. Preload on the odd phases
3 star one territory on the evens (and preload with any spare change)
That gives you 3 stars in each of the Light Dark and Neutral territories- 9 stars is worthwhile in terms of rewards. However, if your guild needs to farm Wat shards you might want to alternate with DS Geo

If you can get your guild mates to commit to adding relics for platoon units, that's by far the best way to pick up additional points. If memory serves, a single unit placed into a completed platoon is worth somewhere in the neighborhood of 700k points. If you're preloading you can spread your platoon units across multiple phases so you can re-use the same characters for platoons in the next phase.

Don't sleep on platoons - they look very daunting and unattainable at the start but you'd be surprised how quickly you'll be filling them if you can get your whole guild to add relics to just a couple of characters. It adds up to big points and more stars.