I think you're making a few assumptions that won't happen. 

First, at some point, those holding Bitcoin will spend them (or would you lock up all of your wealth in one asset class?).  So you won't end up with 1% holding over 50% of the Bitcoins.

Second, the vast majority of users will hold very little Bitcoin (just like you don't put all of your available cash in your checking account).  The use will be more of a flow in, flow out.  For example, I have half a bitcoin in my spending wallet.  I go to the store, buy something.  The store owner takes the bitcoin for the transaction and immediately trades it in for dollars, pounds, euros, etc.

Third, those perks and fraud protection cost money.  You're paying more for goods and services because of it.  Don't fool yourself into thinking the credit card companies and merchants are eating these costs.

The only reason credit cards will continue to exist is that many people rely on them to deal with short-term cash-flow shortfalls.  Although I believe there will be Bitcoin backed cards available soon.