I save-scum if a) I lose dwarves I care about to mistakes caused by the unique physics of DF, and b) I have saved recently enough that getting that dwarf back is worth repeating the work I would lose. If case a) confuses you, what I mean is things like a dwarf placing a constructed floor next to a grate, bars, bridge, etc. and having it crush 7 or 8 people all of a sudden, or the weather changing in 1 frame so that 1-deep water turns into a solid ice wall and kills anyone standing on it.
I use [SPEED:172], I find that this counteracts the low FPS caused by playing on a 9x9 embark and the immense losses of labor caused by stone dumping. The other reason I do this is that dwarf fortress already treats time and space in very relative fashions. Some tasks, like making a table out of rock, might to take a couple days of real time, reflected by a handful of seconds ingame. This holds true. Some tasks, however, such as flipping a lever at the end of the hallway, are taking the same amount of ingame time where they would take minutes or moments in real time. So how does my perception of time in DF improve by simply speeding up everything? The most time-consuming part of any job done by any dwarf is walking to and from places. The most time-consuming part for the player is designating work to be done. Since the two cannot occur at once, I was finding that I didn't enjoy DF as much in the past because it was very low-interaction most of the time. That is, once I designate some stuff, I basically just had to watch the game run, for 2 or 3 or 4 hours. While this is going on, I look around the fort and keep noticing things I need to do. Rather than leave it alone and forget about them, I keep designating more and more stuff and finally the fort is choked to death at 2 FPS. To get massive amounts of work done like stone dumping, mass-producing silk items, etc. I either had to get 200 dwarves and then spend all my time making bedrooms and food and booze and other stuff I already know how to do, and suffer deplorable FPS and therefore get no work done anyway, or I can cap population at something personal and reasonable like 45 where I have time to know and care about all the dwarves and decent enough FPS that work gets done once I queue it. By speeding up the dwarves, the biggest timesink--moving from place to place--is softened, while the relatively small number of dwarves still limits total work output since a given number are always partying, eating, drinking, trapped behind a floodgate, dumping a dead cave spider from across the map, sleeping, or what have you. It just means that once they decide it's time to work, they get a lot done! With dwarves moving and working very quickly I find that I can make huge queues of work and have all the dwarves busy even with indoor work.
I tend to pick a few animals I really like and set a goal of breeding them. These I usually give long lifespans and a bit of natural armor.
I normally mod the rock\stone\metal raws to reduce the needless complexity. I don't need three kinds of pewter, to me pewter is a contaminant in my fortress until someone needs it for a fey mood. Specifically, I simplified pewter to just Pewter, got rid of the reactions for making alloys from ore, differentiated lignite and coal a bit more, deleted many of the non-precious gems which are only semantically-different variants of more commonly-known gems, etc. etc. etc. Basically just changed things more to my liking.
In my current fort, seen as my last DF40d fortress, I have reactions to convert junk stone and plants into other raw materials. The idea is that in exchange for 20 hauling jobs, a smelter job, 15 junk stone, and 5 stacks worth of underground plants, you can produce other items you might need. The ones I use most are 15 rock + 5 dimple cup = 20 iron bars, 15 rock + 5 plump helmet = 20 tower cap logs. Since I don't have magma yet I also make a lot of bituminous coal from 15 rock + 5 tower cap logs.