Subject: Direction of electrical current & fuses, definition of 'ground'

The websites http://www.allaboutcircuits.com/vol_1/chpt_1/7.html and 
http://www.amasci.com/amateur/elecdir.html, confirm my idea that current in 
automobile electronics flows from negative to positive (hence why the 
instructions always say to disconnect the negative battery terminal during 
repairs).  As such, would it be better to put fuses on the negative side of an 
appliance, or will it matter?

Given the second source cited above, would a ground be defined differently 
depending on current direction?  I always thought it was an excess of electrons 
(like the metal in a car's frame), but does a ground have to be positive also 
(is that possible?) to be a "true" ground?

Thanks!

Re: Direction of electrical current & fuses, definition of 'ground'