Permafrost's Vision:

[Lord Rahl]

I imagine a postnukerp where cars have to run on the same fuel as a gas generator, a pnrp where the cars can carry MUCH less, and pet headcrabs can be used as tiny little pack mules. A Pnrp where players have to use electricity in. Order to power a lamp/lantern tool instead of using a wire light or lamp, a pnrp where the combine can choose to target heavily populated areas in an attempt to invade, or zombies can gather in pursuit of the boisterous survivors.

A headcrab plague event- the displayed text can say "you hear a slight shifting of the dirt, accompanied with a feral screech..." where normal headcrabs that cause insta-zombification burrow up from the ground: within a radius of player's props- or player's tools, or something. Make them go after the players directly.
This particular event could have a reward- maybe a rare drop weapon from the headcrab in the form of "deadly headcrab fang" which causes either a lot more damage, or maybe poison, to the victim.
Or it could just be another deadly event to force players into a more cautious lifestyle.

Sun lamps for plants?

I think forges should be able to work in reverse at a different but much steeper ratio, but should also have to be powered by electricity
I was thinking...
With the addition of these nuclear fusion and fission reactors- would it be too unfathomable for the scientist to have access to an "alchemy station" or "Ionizing chamber" or "Ionization lab" which can run on electricity to turn small parts into chems over a certain amount of time.
Maybe make it so forges work in a fashion similar to a minecraft furnace, where you have to wait a period of time while your materials cook/melt into the opposite form. (this idea also applies to my scientist's lab idea)

Maybe a cultivator's food should have to cook, on a stove, powered by electricity. As mentioned by zoidberg in another post,cooking is way too cheap and easy right now.

And that is but a small part of my vision. I will add more later or explain my ideas in greater detail if you comment and ask me to.

[CmdZoidberg]

After the feral headcrab thing, I immediately thought just build all my bases on raised platforms supported by stilts.

I imagine a few of these have been put into consideration already just not spoken of by the devs. I can remember a long time ago someone mentioning that the group feels that crafting as a whole is way too easy at the moment, even with the constant upgrading to include tool limitations it still feels too easy.