To Walk - Use the Arrow Keys, left click, or hold right click.
To Attack - Use the Space bar, Auto Attack Spell, or Left Click.

If you are having issues with NPCs, Mobs, or Items not appearing, there is a fix.
Just press 'b' and open the general discussion board and follow the instruction post #129 and/or #41

Hot Keys:

F1 - Character Menu, Info, Status and etc.
F2 - Clan Menu and Additional Subpath Specific menu
F3 - Friends List. Save Player Names Here.
F4 - Vending and Toggle in game setting in here.
F5 - Turn ?Whispers? (Private Messages) On / Off!
F6 - Turn ?Shouts? (Kingdom Messages) On/Off!
F7, F8 - Turn Volume Up/Down
F9 - Ignore List. If someone is bothering you add them here.
F10 - Option Tab to Turn On/Off many Features
F11 - Spell Macro List. To Set Up Your Spells 1-0. a-j is default
F12 - Fast Walk On/Off Toggle
Ctrl-R - This will refresh your screen.
Ctrl-W - Opens the User List. Can click on names to Whisper them.

Communication:

To Talk - Press the Enter or Key.
Shift+? - Then type in the player name, then enter,
and then type your message and send it with the Enter key.
Shift+1 or ! - To Shout. This reaches further than Normal Talk.
Shift+; or : - Express Emotions. Select a letter and see for yourself.
b - Opens the Boards to Read and Reply to Forum Threads!
g - Press g then type in player name and hit enter to Group!
Shift+g - Toggle On/Off your Group.
m - Press m to Open your personal Mailbox!

Your Character:

s - Opens your Status Tab! Page Up/Down to See your Legend!
i - Press i to open your Inventory Tab! Press Again to Expand List!
Shift+= or + - To Open your Spell List! Press Again to Expand List!
c - Press c then letter of inventory item then comma then another item.
Example: c then a,b Enter. This will swap item a and b in Inventory!
Shift+c or C - Press C then letter of Spell, then comma, then another.
Example: C then i,j Enter. This will swap Spells in i and j in Spell List!

Pick up, Transfer, Drop:

, - Comma Picks Up One Item Under You and Place it in your Inventory!
Shift+, or . - This will Pick Up ALL Items Under You Place in Inventory!
Ctrl+, - This will Pick Up All Items in all Tile Around You! (9 Tiles)
h - Hand an item by letter number or Gold with Key!
H - Hand ALL of an item by letter or Gold with Key!
d - Drop an Item by letter or Gold with Key!
D - Drop all of an Item by letter. View Inventory with ? Key!

Combat:

Space Bar - Swings your Weapon
t - Press t then a letter of item in Inventory to Throw It!
Shift+z or Z - Cast a Spell by pressing Z then letter of spell then Enter
Example: Z then s Enter. This casts spell in s slot from Spell Book!
e - Eat an Item by pressing e, then letter of food in Inventory!
u - Use an item by pressing u then letter of item in Inventory!
w or Shift+w or W - Wield any Equipment in Inventory by letter!
T - Take off item by Prompt in chat window. You can also
remove items from status screen by double clicking!

Miscellaneous:

/ping - check on your connection status!
/roll - roll a 100 sided dice :D

Shift+Q or Alt-X - To Close Out and Leave the Game!
r - Can be used to Ride wild Horses!
o - Press o to Open Doors and Interact with Objects!
Shift+E - Toggles On/Off Exchange Feature!
f - Opens the Group Tab to see your Party!
Shift+i or I - Opens the Creation System Interface!
Ctrl+Arrow Keys - This will move camera one tile at a time!
1, 2, 3, 4, 5, 6, 7, 8, 9, 0 - The number Keys are for Quickcast!
Default is letter a - j in Spell List for 1 - 0.
Use the Spell Macro List (F11)To customize!
Scroll Lock - Take a Screenshot to Remember!
Shift+/ or ? - To See Most of this List in Game!


Thanks to Jacob and Peter to list this out :)