As in I like my gun and I don't want to go out and buy a brand new one when I can spend just as much money modifying and upgrading the one I already have.
You can spend the money. You cannot make your pistol any 'better' than it already is.
I want an overall better weapon by way of upgrades and modifications to my current weapons platform.
I'm going to be blunt in telling you something you've, most likely, already heard.
You are attempting to pick up a turd from the clean end.
Although a spring kit and a fluff & buff cannot hurt neither they nor anything else can make your pistol "reliable and long lasting". You can spend the cost of a new and quality pistol in an attempt to make your pistol "reliable and sustainable" and it won't happen.
When you start with garbage, you end with garbage.
My gun simply won't fire at the moment. The clip also won't lock in place when I try and load it.
Its already broken. Simply put, you cannot make it brokener. Take it apart. Detail strip it. Try to think like the original designer thought. Play with it. This is a very good way of understanding how its supposed to work. Consider it a learning experience.
I am a (still) semi-retired gunsmith. If you insist on attempting to make your Bryco a quality and reliable piece you must start by discarding every single piece of the pistol. Then each part must be refabricated using quality materials. I'm guessing this will run in excess of $5k to have done. Unfortunately, after spending this amount of money you will have a pistol made up of quality parts but of a pathetically poor and unreliable design.
There is no 'fix' for bad design.
Do you begin to understand?