According to the RAF Glossary of Code names:
Intruder – offensive patrols intended to destroy enemy aircraft over their own territory, patrols were usually carried out at night.
Rover – armed reconnaissance flights with attacks on opportunity targets.
And in this link
http://en.wikipedia.org/wiki/Bristol_Beaufort
"The first RAF torpedo attack of the war came on 11 September 1940, when five aircraft of 22 Squadron attacked a convoy of three merchant ships off Ostend (Oostende in Belgium). One torpedo hit a 6,000 ton (5,440 tonne) ship. Four days later, the first "Rover" was mounted; a Rover was an armed reconnaissance mission carried out against enemy shipping by a small number of aircraft operating independently. "Rovers" became a major part of Beaufort operations over the next 18 months."
As to the last question, I don't know. (22 Squadron was in Coastal Command, for example).
http://en.wikipedia.org/wiki/RAF_Coa...g_World_War_II