IWanna Stay with Spencer - S1-E5
Other mistake: The "Fan of Hammers" has all the hammers pointed the same way. But when the hammer goes into the wall, it goes in backwards. It is also there through all the rest of the shows and even in season two, where in "iKiss" it has a black handle. (00:02:35)
Other mistake: When the military barge into Nevel's house, Uncle Roger puts the camera down and you can see it not moving whatsoever, but in the shot from the POV of the unmoving camera the shot is moving.
Other mistake: There is an A stuck to Carly's butt, but nothing touched Carly's butt when she got downstairs. (00:20:30)
Other mistake: When Carly and Sam are pumping the watermelon full of air, one shot zooms in on Carly's finger as she hits the on-switch. The device is turned off as she removes her finger. (00:01:32)
Chosen answer: I don't know how to answer the first question but for your second question, there is going to be an episode after iPWV, called IDate Sam & Freddie which will deal with their kiss from iOMG. IParty with Victorious will not be related to IDate Sam & Freddie.
The I date Sam and Freddie proves that they are a couple.