It's in the name: 'overly optimised'. It's very viable.
Depot A is a challenge for pretty much any build going through it. It is a strange point in the game where the difficulty spikes before you really have a chance to develop your build. It sounds like you did okay, though.
Psi builds can be limited when started out but near the mid and end game become extremely powerful with the right spells and gear. The strength of these full psi builds is from good damage and very high versatility. Near mid to end game you should have a spell for pretty much everything, you will learn what works best for what.
A general rule of thumb is to not worry about crafting until you reach the core (if you haven't heard of it you will soon). It is here that you unlock some high-quality merchants which make crafting higher-quality gear possible. Up until then (and even after, to an X-tent) looted and bought gear is usually better than what you can craft anyway.
I wouldn't bother with hoarding mushrooms to craft psi boosters. Have a large enough stash to make all the catalyst you need for other psi-related drugs but they are so easy to find and respawn so don't lose sleep over it. If you loot and sell as much as you can you will have more than enough money to buy all the boosters you need and more.
If you struggle with carrying weight I suggest getting a lifting belt (Increases max carry weight by 30?) and keep some Rathound and pentapus barbeque on you (both can be bought at various bars and increase carry capacity.
Overall all, this build will dominate on classic as you move into the mid and late game. It sounds like you're fine.