You do have index PHP File 3 KB still located in your casino folder correct? This could be missing and without deleting your temporary internet files you may still be able to connect to it. All usergroups can view casino/index so it is not a permissions setting. The fact that the url works for you but does not copy / paste sounds like some kind of gypsy curse. At the risk of giving bad advice I'll have to let someone more knowledgeable field that one...sorry.
I use the Casino Cash System so I am not familiar with changing the Cash System to VB Credits but Andrews instructions seem pretty easy to follow for us code-challenged folks regarding that.
Integrating with other cash systems
This is fairly simple to do, you just need to change the cash type field under "Casino Settings" in the admincp.
* VB Plaza - Change to "vbbux"
* iCash - Change to "Money"
*
VB Credits - Change to "Credits" (You should also set the cash bonuses to 0 or dissable the plugins for those as they will get duplicated)
To remove the "Casino Cash" field from the admincp dissable the plugin named "Casino admin cash"
Thanks for the kind words. When you get this install finally hammered out you will probably know it better than any of us. Knowing how to install the mod is great, but knowing how to solve problems generated from errors in previous install attempts is valuable knowledge on this thread.
Cheers