although do dogs dive inside with the 'Inside' order too?
As stated above, no.
But I embark with 4 dogs - not wardogs, just "dogs" - twice as many for the same price. Any spare 5x5 area quickly becomes a (temporary) kennel, and my woodcutter trains all 4 to wardogs in a snap*, even without any Animal Training skill. Then they follow him around until they're assigned to someone else.
(* I guess I should really pay more attention next time - I'd guess maybe 2 dwarf-days/dog??? Cranks thru all 4 fast.)
So, if he (or whoever they are assigned to) stays inside, they stay inside with.
Okay, I see what you mean about working areas --
There are few "right or wrong" approaches, except within personal preference. But I (thought that I had) laid out some specific preferences - thanks to those who understood those.
I've got a small (15x15?) enclosure started - so far it's just a single curtain wall to hide - only just hide from line of sight - from the direction the imps would come. (Heh, pay no attention to the dorfs behind the curtain!). Some of the other ideas will be implimented.
Once finished, it will span the brook, so drinking source won't be an issue in the desert heat. And it will connect my (temporary) dining room with the barracks, have a statue garden, AG farms, and my first ballista practice ground, so all that is covered. (Ballista fires point blank into the wall, ammo drops into a wide channel, ramp from ballista leads straight down to the channel, very fast recovery/reload rate with only 1 ammo.)