Cool thread! As a GM, I've run for characters all over the morality spectrum, usually what I've found is that people tend more towards "professionalism" as the main overall goal the longer they play, which makes new characters entering the group trend towards that as well. So, appropriate escalating force, lethal only when needed, explosives rarely. Children are usually off limits, even for the total psychos, though general collateral damage/innocents seems to be pretty dependent on the job- success within mission parameters is the main goal. There are some exceptions- usually insect, blood and toxic mages and spirits are kill on sight, and many characters have other specifics (vampires, Aztechnology, etc. depending on their history).
Usually the team researches local runner culture to find out what the appropriate force level is when starting a job: i.e., in NYC, they use solely non-lethal (if they can), as the culture there is that extractions are a common part of the playbook, and the corps won't come down hard on runners if they don't go out of their way to cause chaos and excess damage while doing their jobs. I've really played up notoriety as determining what jobs they get offered. In Lagos or Bug City, they rock heavy armor and weapons and make examples of anyone who fucks with them (without looking for trouble) as they need to seem strong to be able to work freely.
When they started out, they would frequently use bombings as a distraction for major jobs (choosing a random secondary target to distract cops and such), which worked great in the immediate but attracted a lot of police attention and notoriety, and they've moved away from that overall strategy (though none of those runners are actually on the team anymore, there's been some overlap).
Rape and sexual violence is off the table, in terms of both what players and characters would allow/feel comfortable with. There's one character now who is a skilled pyschologist, who would understand the terror that threats of sexual violence would cause, but would not morally feel that it was an acceptable tactic. We get into some pretty dark stuff in terms of what the team encounters on jobs, but this in the line the players won't cross in my experience.
The 1 time the runners tried to use physical torture, I made them roleplay through it, as I like to make players really feel acutely aware of the outcomes of their character's choices- we didn't go into crazy levels of detail but I didn't want them to just "roll to torture" as I felt like it made it too easy to do. They haven't tried it again, preferring drugs, blackmail, bribery and pyschology these days, arguably with better results. This maybe reflects my personal beliefs about the efficacy of torture, as yeah you will likely get a LOT of info, but it's going to be of very questionable accuracy and veracity.
My occasional character is a very professional sniper, who came out of the resistance to the Japanese Imperial occupation of CalFree. She is obsessive about clean kills and no collateral damage, as her reputation is what she relies on the get work. She has no problem killing for cause or money, but doesn't like to kill outside of that.