see above, searching your house for drugs then finding guns also never needed a second warrant for them to take both and charge you with bothif they had a warrant for the emails and found child porn would they need a separate warrant for that also?
Yes. You have to spell out what crimes you are investigating. If you find evidence of another crime outside the scope of the warrant you have to obtain another.
see above, searching your house for drugs then finding guns also never needed a second warrant for them to take both and charge you with both