I usually use normal xp rate, normal zombie block damage, I double the horde night zombies, and I usually set the zombies to jog during the day as walking is just too easy to get around in my opinion
Open Registry Editor, usually done by typing regedit in start, navigate to HKEY_CURRENT_USER\SOFTWARE\The Fun Pimps\7 Days To Die
Or, you could use Red Eagle's mod to introduce more traders