firewall is an unfortunately terrible skill at low levels; even at higher levels, it’s primary role is zoning in pvp. enchant fire would be a better use of points, as it lets you double any elemental damage you get on autoattacks, which you’ll be doing a lot of.
I would recommend getting the 1 point in salmon in sorc1, as it’s a decent helper for a very low investment. delay a point from familiar to C2, as that’s when the skill will improve significantly.
evocation is only 1 hit. you can get it if you want for the explosiony-ness, but most of those points would be better served getting more bats from familiar.
warlock or featherfoot are stronger overall than C3, but if you’re just keen on having tons of bats or the strongest summon you can, C3’s fine.