Pure Data limits and crashes?

Is it possible for the Organelle to crash if loaded with poorly designed patches?
And what are the signs of a crashed Organelle if it is possible to crash one?

It is possible for Pd to crash if something is designed poorly in the patch, sure. Things like too much complexity for the CPU to handle, endless loops, or incompatible or corrupted files can cause issues.
Usually Pd itself will just crash, but the Organelle will continue to function.

These problems are usually pretty obvious and easy to catch, especially if you are developing patches right on the Organelle (instead of making patches on a separate computer).