Eventually they go into an infinity circuit to keep them from being eaten by Slaanesh.
Afaik, Iyanden hasn't invented Infinity Circuits yet, and if we had one, would we want to put hateful Biel-tan souls in our circuit?
With Iyanden as a middleman, to make Biel-tan look worse.
Attached Transports explicitly share the same organizational "slot" as the squad they're attached to, but you can take extras as Fast Attack options if you decide you need further transport capacity for some reason. This is the advantage that their weapons restrictions are buying.
Needler weapons are significantly less expensive. That is why you developed them to begin with: they're cheaper than your fancy exotic guns, so easy to mass deploy quickly, and still largely superior to Lasguns whose main selling point is being absolutely rock bottom cheap. Equipping all your units with the fancy equipment would push it from "I can do one Detachment per Bonesinger AP with some change left over" to "Three Bonesinger AP gets me two Detachments and change."
In order: you will get a specific Subvote for equipment production (probably with the QRTs as a header for convenience), and yes, single Steward actions will equip multiple Detachments at once.
This isn't as much as you might think, here: recall that the cheap refit I pointed out, for one of your twelve Detachment types, is fifteen a pop for a Forge action. Giving them Starblasters instead would easy cut that to less than half as many covered in the same period for the same action-a direct 1-1 replacement would put the price tag at 542 EP a Detachment--in other words, only nine Detachments and change from a single forge action, instead of fifteen. The Tyrrany of Large Numbers is absolutely something you have to deal with, especially right now when you are having to spend lots of actions on producing equipment, rather than having your infrastructure producing it without intervention.
You should look at the total per Detachment equipment listed in the Detachment descriptions. A 1-1 replacement of las weapons with Starblaster weapons for a Militia Line detachment would be 12 pistols (48 EP, as they're 4 each), 21 rifles (210 EP!, Those things are 10 EP a pop) and 16 Carbines (128 EP, 8 EP per gun), plus an additional 156 EP for the Brigandine armor for everyone. Even dropping the rifles to carbines to save some cost only saves you 42 EP.
