they explain in the Core Rulebook how your character is allowed to walk with an armory, their level is correlated with acquiring appropriate licenses, contacts, and the like for having access to that equipment, it's the in setting justification for why equipment is "level" locked.

as your character levels up, they acquire the required permits/contacts to purchase weapons of the correct item level

(this indicates there is gun control in most of the Pact Worlds, although it's not the same on every world, as outside of Organized Play the item level rules are suggestions rather than ironclad)

why both laser guns and swords are used

Absalom doesn't control guns effectively enough to prevent free-for-all gunfights

Level 1 average people can still buy frag grenades and make an IED.

But it only takes one high-level political terrorist, Devourer cultist, possession victim, or goblin to cause a mass shooting.

Level 1 average people can buy and craft lethal weapons, but not automatics. Level 1s can also get a glamor fusion to conceal a weapon.

Absalom Station is so huge that personal-weapon-sized punctures shouldn't endanger the populace. Further, they can seal or prevent leaks with force fields.

Glamored weapons could be outlawed only if cops can find and identified them with a search, at least after a crime is committed, and punish the user.

getting a warrent and checking for glamored weapons

Hand weapons probably can't puncture the Absalom station hull

Or you read Incident at Absalom Station and realize they have no problem with you wandering off an arriving shuttle with heavy weapons and grenades, and their only response to firefights at the shuttle port is to show up a few minutes later and check the video footage to exonerate the survivors for self defense.

I think that an overarching gun control law isn't going to be universal across the Pact Worlds. It will be local to the area. I see the Pact Worlds as a lot like the EU: individual governments that have all agreed to the same treaties. So while they all agree to work with each other and protect each other, they all have their own individual laws and regulations. Some will allow open carry (Absolom Station is an excellent example), some will ban weapons altogether.