I just run dwarf fortress. I pretend I'm in the matrix when I stare at the screen. I removed the aquifiers because as best as I can tell, you people are all liars when you claim they can be penetrated. :/
I've always embarked with trees. I enjoy cutting them down and building giant wood towers that my dwarves have to live in. The metalcrafting is new though, from about when the crashes started.
That's funny, I embark on aquifers all the time. I actually prefer it to embarking anywhere else, since it's free water starting from any horizontal tile I want.
Incidentally, the easy mode aquifer breach,
"The Chicken Run Technique" was one I stumbled trying to set up quick test forts where I didn't care about risking my dwarves' lives. All you need is to train up your miner to rank 5-6 in mining, (dig soil holes - works best if you only have one miner -) and dig faster than the water can fill up the pit. Connect to caverns, and boom, problem solved. Aquifer flows are much slower than river or ocean flows, so you aren't in nearly as much danger as you'd suspect.
Once you're below, you can easily use the drainage method, or a modified drainage method with an atom-smasher tied to a repeater to eliminate all the water coming down and make a stairwell through as arbitrarily large or shaped as you wish.
Alternately, the easiest method is to just embark on the boundary of a biome with an aquifer and one that doesn't have one. My current embark is half desert and half forest with an aquifer. Just mine down the desert half to get past the aquifer, and tap the aquifer for infinite water. I always embark on biome edges, anyway, since that gives me access to a wider variety of resources. (And deserts are guaranteed sand while forests are guaranteed wood.)
Anyway, to get back to the matter at hand, what have you started doing differently that starts causing crashes, to be specific?
Are these magma forges? Can you shut off forges, but keep smelters working, and see if that causes crashes, or vice versa? Are you melting large numbers of things?
Is the game running or paused when it crashes? What menus were you in?
How many dwarves do you have, and how many items do you have both inside and outside of stockpiles? Are you using quantum stockpiles? Do you have large numbers of forbidden items or items outside of general burrows?
(And again, what year and season are you in?)