Not quite, he'll still yell at you sometimes when you enter the stash ^^
It may also be possible to stash him if you tell him you'll bring him to Regina, haven't done that yet so I can't confirm, but if the quest flag gets removed you'll be able to stash him and he won't yell at you.
Although the yelling when I enter the stash is kinda funny imho.
I returned him too. I hope that in some future content Regina will call and tells us that she's fed up of Skippy's voice or that it's just there doing nothing and it calls Regina 'BAD USER' for not letting him go on adventures, so she gives him back.
I'm only missing Skippy because I gave him back to Regina.
Have all the other ones though.
Would love to have an interactive stash in the armoury, a weapon rack or something similar where you can place your weapons (e.g. armoury of the "Premium House" you get at one ending) as well as an interactive wardrobe
I'm missing two guns .. over 210h in the game and I don't want to start it over just for those guns hope they will be avaiable in some way for those who missed it... like
Psalm - it just didn't drop (I know schemiatics)
and Jackie's gun - I took Vic option so no additional mission for me..