First time playing Astrologian... need some advice/tips

[StarRosie]

Only advice I can give (Since others have covered the bulk of important tips.) In a pinch, Synastry+Nocturnal Sect+Aspected Helios can provide a good amount of breathing room since the shield blocks an amount of damage equal to 150% of the HP healed when the shield is put in place and Synastry ups your healing potency, so this will result in stronger shields. So if things are going south, hit this combo to cover your party with a good amount of EHP, and it will give you the breathing room to pop lightspeed and SPAM THE DAY LIGHTS OUT OF HELIOS!

Also remember to relax and have fun! A stressed healer can be a sloppy healer.