This has been a source of major annoyance for quite some time:

http://steamcommunity.com/sharedfiles/filedetails/?id=565972880

There's a perfectly useful doorframe without a door, but I am never allowed to replace the door!

To me, this is a major failure of foresight, naturally someone would try to replace a missing door in buildings!

150% agree with you there!! Also, either let us scrap all the houses in Sanctuary, or give us the tools to repair the walls and roofs etc... I throw random roof tiles on top of the major holes and they do keep the rain out, but I don't want to see what it looks like up there LOL I will probably move everyone and everything out of Sanctuary soon anyway.

Hopefully they will expand on the building system via dlcs/updates if not there will always be mods that will fix that, though atm without GECK released its limited what they can do with mods so you might have to wait till that.

Knowing the awesome modding community, I have high hopes that they will develop a lot of stuff for the settlements. Can you imagine the stuff we will have through mods? More flags, more pictures, more decor, more building blocks and modules, more furniture, different walls etc. etc. etc. I can see the future and it will be amazing!

Actualy most of what you listed is already in the mods, its just that certain things are not possibile without GECK, but there has already been plenty of stuff added to building module with mods.

Oh seriously? I haven't even checked on any FO4 mods yet. Still busy just playing the vanilla game! I'll have to look through the Nexus mods and see what's out there! Thanks for the heads up!

hang doors and repair roofs. this is my biggest complaint with the settlement making system.

Np mate and a sugestion try to avoid any mods that arent made with FO4edit, cuz those are much more likely to cause instabilties or save game coruptions.

Pretty much in all of the settlement construction are adjustable pieces to scale to the gaps they have to fill: doors that fill doorways, wall sections that fill in less-than-full-sized gaps between sections, fence sections that fill gaps, etc.