I have frequent lag and crashes with (only) this mod installed.

It did the freeze the game the first time I tried to loading it with this mod. After a second boot it did work, though. However, this mod did prevent me from touching the "dark orb" in Tatsu Park needed for the total ending .

It was doing the same thing to me until I remembered I had mods manually installed as well as ones from the workshop. After I removed the manually installed ones it seems to work fine.

Could you post the error report?
There should be a copy to clipboard button on the error screen.
(If the game window isn't opening at all, I'd recommend removing all mods, including the Mods mod and launching the game again in an unmodded state before reinstalling your mods again)