While I really like this game there's the little part where one must have to look in every nook and corner to unlock those annoying cards as severely detracting from the experience.Is there any cheat out there where I can seemingly unlock all cards?....

Not sure, it might have been possible with Powermad (a mod for Painkiller), but I'm not sure where you could find it anymore.

Other than that, I don't see why do you want to unlock everything if you're cheating.

Ah, here we go
http://www.mediafire.com/?xuwv0jp69cbptm6

There is an easy trick to instantly unlock 23 cards (out of 24) from the main game. All you have to do is start a new game for the addon (Battle out of Hell). This makes all cards from the original game instantly available except for one which can only be obtained on Trauma difficulty. Now simply start a new game for the original Painkiller campaign and choose to keep the tarot cards.

Never thought of that as I owned the original Heaven's got a hitman before getting the Black edition. Even after years of playing I still learn new things, fun stuff.

Yeah, I also hadn't noticed this was possible until yesterday, despite being a huge fan of the original game and its addon.