Electrostatics, capacitor question

[potatocar]

1. Probably a stupid question, but what are the +'s? Are they just representing the fact that there is a lack of electrons on that plate, or are those actually some positively charged particles that rearrange themselves like that?

2. Do they actually rearrange themselves like that? Does the surplus of electrons really move to the edge of the plate like that? If so, is it like in the picture, or are they outside (on the surface) of the plate?

3. Why is there no electric field inside the plates? If the charges aren't equally distributed, wouldn't there be electric forces? Are we assuming it's a uniform field?

 

[mfb]

Are they just representing the fact that there is a lack of electrons on that plate, or are those actually some positively charged particles that rearrange themselves like that?

Both. You have positively charged atoms there, and they are positive because some electrons are missing.

Does the surplus of electrons really move to the edge of the plate like that?

They do. A small fraction can be found on the other side, but that is negligible for most capacitor setups.

3. Why is there no electric field inside the plates?

In equilibrium, the field in a conductor has to be zero, otherwise current would flow along this field and neutralize it.