Playing with a mixed character

I bet a summoning master is badass, but I wouldn't recommend that for a mixed type; the Familiar spell is pretty useless without optimal magickal aptitude. For a mixed type, if you're going to master any school, Temporal is usually the best way to go.

EDIT: Control Beast is another great spell for mixed types, regardless of aptitude you can get pretty powerful allies at very low level. It's limited use but you get a lot of opportunities to use it, and you can peacefully release animals with Charm Beast, which is another great ability to help survive early wildlife encounters.

On the tech side, molotov cocktails are pretty cool even without throwing skill. The damage is slight but the crowd control is highly useful, esp for ranged fighters. The ingredients are cheap and plentiful and the product is light-weight enough to carry a load of them and use them freely. I'd say these are better than the explosive grenades, which for the cost in character points weigh four times as much and does an unimpressive amount of damage. Compare one point of explosives to three points for the Call Winds spell, which is also nice but leaves you with an unnecessary spell, Poison Vapors, for the cost of a point.

Btw, does aptitude have an effect on the results of crafting? For duarables like armor, guns, weapons, it has an effect on usage but doesn't seem to affect the product. How about consumables and combustables, do you get more out of them with more tech aptitude? Playing a balanced aptitude character could be why the grenades were so disappointing.