Are shop intended to drain all of the power of ship docked to them to prevent people to shoot while docked to a shop ?
Yes
In that case shops don't do so if the sector isn't unloaded at all.
Most of the time nothing works if a sector is not loaded.
On the other hand, if they do drain all of the power and it isn't intended well... It's a problem too.
It is intended so it is not a problem.
When advanced shops first came out they had unlimited power. Anything docked to a shop is also invulnerable. So how Godlike do you want it to be? You could make very nasty use of this. Like camping on the spawn shop at 2 2 2 or anywhere else where such a shop might be located.
So it was nerfed from unlimited plus power to unlimited negative power. Though you can still have ships turrets that are self powered fire at people. While making use the shops invulnerability. The ship that they are attached to then gets his power drained but not the turret attached to the ship.
Currently Advanced Shops are mostly free parking spaces. Excelent for Nomadic people. Or those people who Home Base overflows with ships and need to park them somewhere else to lower entity pressure.
There is even a
server.cfg setting that allows all shops to have basic rails for parking.
SHOP_RAILS_ON_ADV = true //Advanced shops will have 4 rails dockers that can be used like a neutral homebase (anything docked is safe)
SHOP_RAILS_ON_NORMAL = false //Normal shops will have 4 rails dockers that can be used like a neutral homebase (anything docked is safe)