The grand design needs to be nerfed or made into a hardmode item

[SpectreFKD]

The motion idea reminds me of Indiana Jones

Nice find @Snickerbobble with the door bypass!

Anyway, I quite like the motion detectors and invisible wires pre-Golem idea. Even without the Grand Design the pressure plates are too easy to spot out (and then there are the traps themselves as well). It'll make it a little trickier to get through the temple.

Only thing I'd add to your idea, as darthmorf mentioned before is the inability to break said wires (and potentially break blocks) until golem is defeated - this then will make the temple a real challenge!

 

[ArmyFrog]

Maybe there could be a special type of lihzhard wire, the same way there are lihzhard pressure plates, that connot be detected/broken by the grand design.

 

[Ami]

Lens is amazing, but you get it late enough that it's not OP. It did singlehandedly save one of my characters by exposing a pressure plate/explosives trap that I would have fallen on during my hunt for heart statues (light shroomite claw digging hellevators), but this was in hard mode already. Prior to the lens, you can still put boulders/traps/pressure plates in the hotbar to see wires.

Furthermore, it's not the grand design that's OP, but the wire cutter. You don't even need to see wires to disable them. Turn on smart cursor, fly through the cavern holding click, then come back and light it up with torches.

 

[SpectreFKD]

Disabling underground traps with the wire cutter isn't as much of an issue as it is with the jungle temple - since that's the main 'gimmick' with it - THAT'S what needs protecting from disarming until golem is defeated at lease once