How do I delete all my symbols except those in two user-defined quotepages.
You can do this manually, by opening the .All Symbols quotepage and deleting the symbols one at a time, by clicking on the ticker symbol in the quotepage and then clicking on the red trash can icon in the quotepage toolbar. You can delete ALL the symbols by clicking on the "Ticker" column heading and then clicking on the red trash can icon on the quotepage toolbar. However, that will remove the symbols from other quotepages as well.
You can create a scan (File > Open > RTL) as shown below: