You have an interesting idea with the pheromones, don't know if I can afford them as I haven't totally nailed down all my gear/wares yet.
As long as you're under the gear cap, you might consider them. For example, tailored pheromones 3 is 45000Y or 9 BP. You save 1 BP versus Charisma 2. However, your rolls are now 3 rather than 1. That's no face, but it's something. All of this is dependent on how your group handles social skills and GM aggro levels.
Now for
Arsenal. Unlike
Augmentation which more or less gave you options,
Arsenal will make you more powerful. The two most important things are stackable armor and weapon mods.
But first, the weapons! Because blades adds to your melee defense, you'll want to have a blade ready to defend yourself. I know you're got a regular knife and that's good. You might want a ceramic knife for MAD scanners. A nodachi is -1AP better than a combat axe. If you want something less glorious Nippon, there's the vibrosword which is forbidden. A bayonet is a decent idea if you spare the mod slot or barrel slot. Either way, be sure to get personalized grip on everything! It's +1 rolled die for basically nothing.
As for machine pistols, you have better options now than the Black Scorpion now. They are the FN 5-7C and Ares Crusader. The FN 5-7C has 1 point of internal RC which is very valuable especially in a machine pistol. The Ares Crusader has an extremely deep clip. Most people like the Crusader, but I'm a FN 5-7C man myself. Either way, it's a good idea to mod them for FA fire if you use gas vents. I personally like suppressed fire on my concealable weapons.
Here's my recommend setup for the FN 5-7C:
Chameleon Coating [2]
Personalized Grip [1]
Underbarrel Weight [2]
Reduced Barrel [1]
Smartlink [Top]
Sound Suppressor [Barrel]
Concealable Holster [-]
Now, you have a fairly concealable (-4 to sight, +0 for patdowns) weapon for suppressed burst fire. For some reason, I can't seem to find the last point of RC I need for RC 5 without getting gas vents and losing the sound suppressor. A 20 round magazine (happy CanRay?

) will give you 3 passes of fire and that's enough. The MP9 from
Gun Heaven is better if you ever get that book since it's got a foregrip (which machine pistols can't get otherwise).
I like SMGs and Umaro's examples typically a lot of examples of good SMGs to choose from. Top favorites are the Praetor (2 slotless recoil comp but forbidden) and the SuperMach 100 (if you can get the recoil for SnS spam). But I can see the argument for sticking for assault rifles. If you go down this route, you can make a fairly concealable SMG as your "sidearm" at least.
As for assault rifles, the Alpha is still the best. Sadly it's forbidden. If you want a restricted assault rifle you can keep in the truck, you'll want to mod an AK-97. As for the Ares Alpha, I'll drop the extended clip and extended barrel. Range modifiers are pretty lax in SR4A and the clip will last you 4 passes which is more than enough. I'll get a chameleon coating so you don't reduce the usefulness of your ruthenium outfit discussed. You can also drop either the personalized grip and foregrip and get a shock pad instead. After that, you can get what you want.
Now for armor! The big thing
Arsenal introduces is stackable armor. FFBA and Securetech PPP both add to your armor values. FFBA not only adds to your armor value, it also counts as half encumbrance. For example, here's a good pink mohawk (i.e. when subtly doesn't matter) outfit (thanks goes to Umaro):
Full Form Fitting Body Armor 6/2 (3/1 for encumbrance)
Securetech PPP System Shin Guards, Forearm Guards, Leg and Arm Casings, Vitals Protector, Helmet 2/6
Armor Jacket w/ Gel Packs 9/7
T
hat gives you 17/15 armor which penalty. You can't wear this to a party due to the armor jacket and the gel packs are restricted, but it's fairly cheap.
Your Body is high enough that it's actually hard to find non-silly outfits that are more discrete than the above. But I'll try. Also public acceptance of full FFBA and helmets varies from group to group. My group views it as acceptable especially since most of the body is covered anyways and trode nets making headgear quite fashionable. Other groups differ.
But here's my attempt at a completely discrete outfit you can wear to a party:
Half-Suit FFBA 4/1 (2/0 for encumbrance)
Vashon Island Steampunk Overcoat, Vest, Slacks, Shirt 7/7
Securetech PPP Securetech PPP System Shin Guards, Forearm Guards, Leg and Arm Casings, Vitals Protector 2/4
Moonsilver Line Scarf 1/0
Helmet (assuming there is a suitable in fashion variety)1/2
That's 15/14 armor. Not as good as above, but quite nice. You can get the full 17/15 above, but it requires full FFBA.
Now for the ruthenium coating. It really does help you hide as it gives you a -4. Now what you can and can't coat is vague. I'm of the opinion that something that covers most of you works and you can make a ruthenium poncho you carry around. Others take a more strict approach limiting to armor suits and the like. If you go with the later, I'll grab ruthenium coated full body armor at some point for sneaking.
Lastly always be sure to mod your armor with stuff like Chemical Protector 6 and Nonconducity 6.
That's enough for now. I might cover the rest of
Arsenal at some point.