Jesus, 70 years? No wonder why Tia's so uptight. ;D
Actually, I was thinking about the whole Tia and other crew member's concerns about going back to Omega, and hopefully this will alleviate any concerns about them running into their pasts or whatever reason they're afraid to go back.
Omega is made up of a lot of gangs, and it's not just Blood Pack, Eclipse, and the Blue Suns who control large swaths of the station, they're just three major ones that happen to be the most powerful come Mass Effect 2. Even by Mass Effect 3, they were brought down enough that the Talons ended up becoming major players that largely replaced their influence. It's not unreasonable to assume that years prior to ME1 that a similar dynamic exists, and there's a very real chance Hellis and I will introduce other made up gangs that are key players in certain parts of the station just to give an idea of the diversity going on.
As such, not every docking space is controlled by those three gangs, and I don't think Aria would allow that because that's a lot of power right there if they have a monopoly on every single docking space. The gangs tend to control districts, and often times, that leads to turf wars and shifts in power. As for our crew who have a history with those guys, keep in mind these are huge galaxy-spanning organizations that operate everywhere with massive numbers of members, so it would be an insane coincidence for your characters to be recognized by anyone they knew, and even if they were ID'd, chances are word wouldn't leave the guys who made them because somebody's probably dying in a gunfight. Security footage and databases also aren't really universal across the station, and land changes hands way too often to risk having sensitive information stored in all but the most secure locations, so it's not like most sections controlled by any particular gang will have a database of wanted individuals, and even if they do have people who are on their shit list, that's like finding a needle in a stack of needles. I mean, shit; Zaeed openly walks around with a Blue Suns tattoo on his neck and he struts around Omega like he owns the place.
TL;DR= Your characters will be fiiine. Unless I'm a dick and have the only people who will recognize them step out of the washroom and have a Kill Bill moment.