If it's in fact an ABit system board you should check the BIOS as it may have have better descriptions.
Regarding acpi -t, sensors(1) is checking both acpi and hardware devices it knows about. In a perfect world sensors(1) would report a superset of what acpi is able to report.
It really shouldn't be possible to overheat a laptop unless it is operated in a rather hot environment. It's more likely that the configuration file or BIOS settings are off, or perhaps some filters need cleaning. If the notebook heatsink was installed using thermal grease, that's known to not age well. (However, thermal grease is unlikely to have been used for original production.) You might be able to regrease it or use a modern thermal interface pad. Don't remove the heatsink unless you are prepared to throw away the old thermal interface and install a new one."