1. Yes, read the Fine Manual. That would be a great idea
2. No, there is no monolithic config file. The config for each array is stored on the array itself.
Information about how to find the various arrays is stored in /etc/mdadm.conf.
It is possible that more info could go there. e.g. setting stripe_cache sizes etc. But without a concrete
description of what problems you see, it is hard to address them.
3. I agree, a GUI would probably be nice. I don't write GUI's. Maybe somebody else does.
4. visual monitoring tool - find one that you like (gkrellm isn't bad) and if it doesn't monitor what you
want it to monitor, ask the maintainers to improve it.
5. I would need more context about the error message to comment usefully.
6. A degraded raid5 array won't start after a system crash precisely because it is in fact a broken array.
raid5 cannot withstand multiple failures. A miss drive plus a crash is multiple failures.
If you want to discuss md/raid further, I suggest linux-raid@vger.kernel.org would be the best place.
