ok so had this game on the old pentium 2 and played the shit out of it . went unnoticed by the big gamers but always good to find these little gems. in fact i think i still have the big ass box for it in storage somewhere. Any hows found it on gog for mac ( iwill get a pc for gaming again soon, growing up soughta puts this fun things aside) and my problems are;

>>>I Cant use my F keys (ie f1 f2 f3 etc)
>>>and i cant remember what the go is with left hand right hand, can i use the sword and shield at same time?

anything else i should be remembering?
thanks.

Look here for the keybinding patch so that you don't even need the F keys: http://www.gog.com/forum/realms_of_the_haunting/patch_to_allow_changing_keybindings

As for your second question, you can only use one hand. The sword and the shield can only be equipped separately. There's no need to use the rusty sword, since you get the pistol at the beginning and the shotgun soon after starting Chapter II, while the shield is useful in only one specific situation in the entire game, and even then you can do well without it if you've got quick reflexes.