Thanks guys for all the tweaks, I can finally play Postal 3 and the load times have been vastly reduced.
On another note, I've been tweaking the game to my liking and found a way to make the "weemote" key -toggle- between the zipper and the last weapon, just like in Postal 2.
If anyone is interested just ADD the following to your autoexec.cfg and replace "r" to any key you want.
Alias weetoggle "weetoggleon"
alias weetoggleon "select_weapon weemote; alias weetoggle weetoggleoff"
alias weetoggleoff "lastinv; alias weetoggle weetoggleon"
bind "r" "weetoggle"
Also I have fixed some missing sounds from game_sounds_weapons_p3.txt. If you want to try it you can download it from here: http://www.nicolaspeople.com/ch3rokeesblog/wp-content/uploads/2013/03/game_sounds_weapons_p3.txt
(right click, save as...) and place it over "...\postal iii\p3\scripts\sound"
As always make a backup of your files just in case.