@Death Dragon: The crash bug is known in general terms, but not the details. Equipment used by dorfs when going on raids are probably removed from the fortress when the dorfs leave, but remain allocated to the squad positions. When the raiders return the equipment is probably returned to the fortress and marked as free, but remains allocated to the squad positions (making it possible for the same piece of equipment to be allocated to two different squad positions (unknown if they can be in the same squad) concurrently. Somewhere in that process completely unrelated items, frequently very early artifact "books", can show up in one or more specific item (such as e.g. specific armor pieces) militia member equipment lists. Somehow the source from which those lists draw their information has been corrupted, but it's not known what that source is. It's likely the crash happens when dorfs are trying to get new equipment, and the code tries to process one of these garbage items to determine which one is "best" and tries to evaluate fields that do not exist in the item.
If the rate at which wars happen changes the DF worlds run the risk of descending into smoldering ruins where everyone is at war with everyone else (and the number of necromancers explode if the secret cap allows it and there are sufficiently many survivors to recruit from), unless there is something that compensates by increasing the rate at which civs make peace.
@Telgin:
The attack triggers are based on pop, wealth, and exported wealth, not on time. However, you usually won't get a pop over 80 (the default civ pop trigger) within a single year. If you raid early you forfeit the pop trigger protection (at least with regards to that civ: I don't know if it's removed completely, but it wouldn't be unreasonable). Note that wars are between civs, so starting at war just means your parent civ is at war, but your site is removed from the potential targets list until the siege trigger protection is lifted.