There are some decent ideas at work here but the whole thing is marred by poor execution. Also, am I right to assume that some of this (especially the last part) is modified from a workshop-created map?

Screenshot taken with 'r_drawclipbrushes 1' enabled.
This image portrays exactly what is wrong with this map - design decisions that make no sense at all to the player. If you don't want a player to be able to jump/portal/walk/etc. somewhere, don't just put an invisible player clip brush.
There are other places where the player presses a button and it opens a path that stays open... unless you touch the floor (to prevent the player from taking a particular path). You are obviously trying to prevent certain methods but it just comes across as bad design.
The puzzles themselves are very lose in that you can often complete them in (most likely) unintended fashion, making some of the puzzles trivial in nature.
Visually, the map looks like you were trying to make it interesting and then got tired of trying about half-way though, said screw it, and then then compiled. It lacks any sort of detail in some areas and indicator strips are usually bad or absent.
It's a good effort, but you should put in some more time to fix the plethora of issues that currently exist.
Also: after pressing the button in the last room that turns off the fizzlers, the game sound stopped playing and I was hit with a crazy amount of slow down. I saved and then loaded to fix the issue.