Many of the things the outlaw organizations do are done by the Concord factions. The Amarr have drugs and slavery. All four factions raid each others' space (in missions and events), just like the outlaws. I'm sure all the factions do illegal research. The only difference between the outlaw factions and the legal ones, is they exist outside of the Concord hegemony's direct influence. They aren't cowed by the DED's threat (and application) of force and so have no obligation to obey the values that Concord advocates.
The Amarr produce one drug and it's antidote to control some of their slaves. They are the only Empire to do this. The Angels and Serpentis mass produce a wide variety of drugs for smuggling into the empires and sale to it's citizens to profit from all the misery this brings.
The Amarr maintain slavery in their own Empire and has outlawed taking slaves in other areas, they maintain slaves for ideological reasons and generally treat their slaves well - they expect them to be come Imperials at some point. The Angels and Serpentis and others enslave whoever they please from anywhere purely for their own profit and will work their slaves to death eventually, thus needing to capture more.
All Empires commit to cloak and dagger style black ops operations for a variety of reasons that they justify as needed. From what I have seen apparently civilians are rarely cough up in these. All the outlawed factions raid and pillage for loot, kicks, slaves and other savory reasons and generally target civilians as much as they can, because military targets are harder.
"I am sure all the Empires do illegal research" is not viable because IIRC there is no known PF source to say they do, while we know that the Serpentis at least constantly develop new drugs and boosters that are declared illegal for good reasons. They don't give a shit - other people's misery is their profit.
"The only difference" between the outlaws and the Empires is that the Empires have stable and generally civilized and often pleasant societies to live in. While it varies from Empire to Empire their is generally social security of some sort, legitimate and non-corrupt police and military forces for security, functional infrastructure, good, actual honest jobs and a plethora of other hallmarks of great civilizations. The outlawed factions can't boast even half of this, and their only known export and/or relationships with others is pain and misery in abundance. Outside of war-times and generally in war-times as well the Empires manage to remain somewhat civil with one another.
The Outlaws exterminate whole cities for resisting their demands, steals what they want, kill whoever they wish and abduct people as they please, to do with as they desire. This includes but are not limited to; enslavement into illegal drug manufacturing where you may end up having your very face cut off and sold, being bleed out until dead, the right to watch your family get bleed out before they do it to you, abducted and ransomed, often without being freed, enslavement into the sex industry and the joy of becoming a sex-slave, and possibly conscription into the crews of pirate ships where you assist in all these and more.*
Also, the Empires are not "cowed" by CONCORD - the Empires MADE CONCORD, and said organization takes a dim view of the pirate factions for a long list of very good reasons. None of the Empires are in any way perfect, they are all defined among other things by the fact that they have limits and borders they are very loathe to cross, and that as individual entities they are honorable and civilized to a fault despite of and partially due to, their individual flavor. There are many endearing and forgiving attributes to balance the relatively few dark spots on the Empires, there are few endearing attributes to the host of dark shades to the outlawed factions.
*I could swear I've read of this or heard of it somewhere but can't recall where, take this with a bit of salt.
@Vincent:
I disagree to your assessment of the Serpentis but I'm not rich on time right now. I'll respond to this a bit later.