You can set 3D items to only show during replays or keep them always hidden.
Ectoplasm Tori is a full body set so it's obviously going to affect performance on older hardware, that's the expected behavior.

If you're sure your PC is capable of running Toribash at proper fps without any issues, make sure your graphics settings are set up properly. This thread may help if you have Nvidia graphics: https://forum.toribash.com/showthread.php?t=626543