cURL is one of the most used C libs and is an example of good quality C code. If you follow the style used there, see e.g.
https://github.com/curl/curl/blob/master/lib/dynhds.h (and associated dynhds.c) you will be good.
Looking at the source of some of the old game-engines from the era that have since been released as open-source can also be helpful, like https://github.com/id-Software/DOOM.
In both cases notice how simple and elegant a lot of the code is. There is already enough complexity inherent in the problem they are solving, and that is where the focus should be.
Any IDE with a working language server to make it easy to jump around and refactor should work fine. Limitations might be due to the C language itself?
Error handling on such a fixed platform does not need to be super-advanced. You should always be within the confines of the system so there shouldn't be much that can go wrong. If stuff goes wrong anyway just being able call a function Fatal("FooBar failed with code 34") when unexpected stuff happens and have it log somewhere to be able to dig around should be enough. You never need to be able to recover and retry.
Make sure to use https://clang.llvm.org/docs/AddressSanitizer.html or a similar tool when developing outside of the PSOne.
That said, consider statically allocating global buffers for most stuff and avoid using the heap as much as possible. This will give you deterministic memory usage, no overhead, and simple code.
Good luck working within the confines of the PSOne! Many hackers have pulled the hair from their head on that platform ;)