Disable background scan:
Menu > Setup > System > Customise >
Disable background scanning
Default is no. Change it to yes.
To remove all channel data:
Issue the following command.
Please paste it to avoid issues (link to guide in signature)
Code:
init 4 && sleep 10 && rm -rf /etc/defaultsat.tar.gz && rm -rf /etc/enigma2/lamedb && rm -rf /etc/enigma2/*.tv && rm -rf /etc/enigma2/*.radio && rm -rf /etc/enigma2/*.del && init 3
You will lose all your bouquets and channels. Run ABM again, and you will only have the chanenls that ABM makes.
EPG search will still work when you have chanenls. When you search the EPG, the chanenls on your system are checked. As you will only have the viewable channels, that should be your problem solved. Hopefully.
Sorry, can't answer the other questions. Don't think it is possible though.