So I'm gonna rebuild my spike strip. I want a push on the pressure plate to get the spikes to shoot up, and a release to get them back down. So, here's my plan. Hopefully I understood the conditions well, which state that
all conditions must be met for a trap to be sprung.
1) Build a lever and pull it.
2) Link all the spikes to the lever.
3) Pull the lever. Spikes retract.
4) Build pressure plates and link them to spikes.
5) Pull the lever. Condition one met.
6) If an enemy steps on the plate, condition two met, spikes shoot up.
If I want to temporarily disable the spikes, I just pull the level so that condition one is never met.
ALTERNATE METHOD. I'm not sure this even works...
1) Build spikes in a checkerboard pattern.
2) Build a gear assembly close to a river.
3) Link the assembly to a lever.
4) Link all the spikes to the lever.
5) Build another gear assembly next to the first one.
6) Build a water wheel.
7) Link the wheel to the gear assembly. This should make it so the spikes continuously shoot up and down.
Pull the lever to disengage the assemblies. Time it so the spikes are retracted.
9) Build spikes on the remaining free squares of the checkerboard and link them all to the gear assembly.
10) Whenever required, pull the lever to reactivate the checkerboard spike strip and pierce whatever comes through.
Eventually I plan on something that will completely obsolete this: knowing my river is infested with carps, I will create an artificial lake that surrounds the path leading to my fort and line the sides with floodgates all connected to the same lever. The gates are above water but horizontally linked to the ground. I will also build one drawbridge over solid ground at each end to block escape when the lever is pulled (and the drawbridges won't be blocked by petty things like forgotten socks. This will thus trap invaders in the corridor, and I can then wait for the carps to feast upon them. This takes into assumption that carbs will attack gobbos, of which I am not sure...