When you take over The Castle when helping the Minutemen certain scripts (at a guess, I'm a hack when it comes to modding.>.< ) run that clean up the mirelurk nests and stuff. Didn't seem to be the case when I raided it and Preston is a rotting corpse at the Museum. So maybe, as the place is special, have a special raid quest for The Castle if Preston is dead and you have the perk. So you and your raiders go in, kill the mirelurks, mirelurk Queen, and place is now yours. Then you can power up the transmitter and create Raider Radio that will relay Red Eye's broadcast from Nuka World. Or, could blast royalty free music, like heavy metal or something raiders would like to listen to. Then a raider says they'll 'hire' some of the locals to clean up the mess and make it ready. You go away, come back and the mess is all clean and ready for you to start building. Then one of the raiders says they found something in the basement when the 'hired' help was cleaning. This leads to the same basement Ronnie would have shown you if you did this as a Minuteman General. But in this case the tour is self guided and the terminal she enters her password into (after you wipe out Sarge) is accessible for you to hack. This leads to the Armory (and the weapons workbench ) and artillery. The button to open the door is active so you can open it and start setting up artillery and a merchant to buy more artillery smoke grenades. :D This is just an idea, but, at least I think it's a neat idea.