I'm not sure whether any of the issues you mentioned come from ACPI. There are some bugs in BIOS and provide invalid ACPI table, which resulted in the error messages. But, AFAIK, most of power-saving issues are not about ACPI but about drivers. The power on/off is a different story, though; e.g. if the machine gets turned on spuriously, it's likely something to do with ACPI. But some breakage after PM or runtime PM is mostly a bug in the driver.