Reassembling Striker Gun Without Striker

This applies only to Glocks. Since the striker retains the slide cover plate in the Glock design, you could get it put back together, but you'd have to keep an eye on the cover plate since it would be retained only by friction. If you just wanted to do it and then set the gun down and have it look like it's fully assembled, it should hold together ok.

You should be able to rack the slide too, but I wouldn't want to manipulate it very much. If the cover plate does come off, the extractor plunger & spring are going to be launched in impressive fashion, likely followed by the extractor coming out of the gun and the firing pin safety and spring coming out of their proper positions.

The trigger would be dead without the striker to catch and tension it when the slide is racked.

There shouldn't be any problem with the gun locking up or being hard to disassemble. In fact, having the striker out of the gun would simplify disassembly a bit since there would be no need to release the striker before pulling down on the disassembly tabs.

If I wanted to disable a gun and make it look like it was still functional, I'd probably get a dummy barrel like this one and paint it black.

https://cpwsa.com/glock-specific-parts/753-glock-training-barrel.html