Im gonna go ahead and copy the other guy and give my ideas in this manner:
FACILITIES
PIRATE MARKET - a 2x2 facilty that becomes available after you've researched a collection of guns and ammunition you can manufacture. As the name implies it's a clandestine market where mutants can peruse the weapons and ammunition your gals make at home, it requires a couple of runts/workers to make who will be permanently stationed in it to manufacture a steady stream of the items that will be on sale on it, at the end of every month you will receive a random (but still sizeable) amount of profits in the form of credit chips. Also, during base defenses the facility will spawn random armed individuals that will defend the facility with you, and also maybe it can come in a 3x3 version too? (sorry if this one's a bit convoluted, it could be simplified probably.)
NANCY'S HARBOR CAFE (name pending) - 1x1 (or maybe 2x2 as well?) seedy tavern where not only do the gals have a drink and relax (speed up in recovery time and works as a cultural center) but also, mutant outsiders and travelers stop by to have a taste of your X-Grog, ressupply and also will help fight off base assaults.
WATCH POST - a small closed up cubicle where a hired gun and/or a gal is stationed to shoot at intruders out of small windows. The squatter you hire to the guard post has a chance of spawning sleeping on the job. Features some extra storage space and can be built over.
WEAPONS -
Flare Gun - when NV is a bit scarce, especially in the early game night missions, it would be helpful having something like this to light up farther away areas when an electro flare or magna-lite doesn't quite reach and can be used as an actual weapon too.
COMBAT UNITS -
Armored Hyena Rider - Exactly what it means, a zone hyena rider upgraded with aqua plastics to make it even more resistant to small arms fire. Maybe there could go further and have a more upgraded one with a refractor.
Sabertooth Tiger - Turns out they're not extinct somehow, and they're being kept in captivity by the factions for their own purposes. After liberating them in a special mission for it, you get to tame them and either use them as beefed up dogs or ride them into combat as an even faster hyena with less health. Has an armored version too.
Hyena / Sabertooth /Gun Mount - an armored Hyena or Sabertooth but with an assault machine gun mount on it's side. Just like Metal Slug!
Autodog - point reward from the bank or Jack maybe? a four-legged ramshackle automaton with a special Sonic Bark attack that hits enemies in an area in front of the autodog, reducing morale and dazing them.
MISSIONS
FULL FRONTAL ASSAULT - You get a tip off about a gang of highwaymen/raiders about to have their way with a group of captured slaves and it's your chance to get their discarded loot AND save the damsels for profit and infamy. You cannot bring any male soldiers and are restricted entirely to naked with no weapons, but so are all your enemies in the mission.
Aaaaan that's it, im not very good at balancin stuff so if any of this is broken or doesn't work just let me know lol