The easy way is to save one animated primrose as a vob and load that into the ecosystem.
To animate primrose: set end keyframe; then change properties such as droop, leaf size, etc and set first keyframe. Right click in object properties to save object and save as a vob. This won't create variation in the animation, to do that you would need to save out several different animations and add them all to the ecosystem.
Looks good I just tried it with ecosystem paint and 11,000+ primroses. No noticeable affect on system resources. David

The Camera Level option is on by default. Not really hidden, its the very first item on the first tab of Object Properties! Once turned off you can roll the camera. I haven't been able to roll with the SpaceNavigator, neither does it allow rotation around an object, unless someone knows otherwise?

The softness is odd. I'm sure lots of us watch the end of a render and would notice this if it was regular! The first test is for someone else to try rendering your scene.