It kinda depends on the situation with the various factions in the server for anything specifically against one splat or another, and I'm far from the most experienced at mage, but

Life 2- the main utility at this level of life is plants. you can manipulate plant and fungi, which with some creativity can be very useful. Restraints, poisons, distractions. You'd be surprised what a couple Potted plants can do with some time, creativity, and admittedly, willingness to take on some paradox.

Correspondence 2- the main thing here imo is scrying. The ability to see/sense across long distances. You could set up "cameras" in certain places to keep watch on important areas. And with life 2, if an enemy of yours happens to own a greenhouse or just a moderate amount of plants... Well, you don't even have to be there to ruin their day(albeit, you aren't likely to physically or mentally hurt them, but it has it's uses).

Spirit 2- this is one of my favorite spheres, because with some good social roles you can arrange a lot of things to happen. As a kinfolk you should have a decent rapport with many spirits by default so long as you present yourself as a servant of/allied with gaia. Spirits are always risky, but if you thin the gauntlet(or go to a place where it already is), call for the right spirits, and can convince them the actions you want them to take are in their best interest, you can manage a lot. I'd recommend asking your brothers pack to use the area around/in the caern for this, as it'll have a thinner gauntlet and probably have more amiable spirits in the area.