I've flown EWR-YYZ a few times and the answers are definitely YES, NO and YES.

There are no RCC's in YYZ only MLL's.

Also the AC lounge in EWR is actually a USAirways lounge - not an RCC (nearest the Air Canada gates).

The RCC is much farther out (I think in a different terminal). Also the Diners Club lounge (the only one in USA) is also in a different terminal than the AC gates.

Unfortunately, through they have been trying, United and AC gates are far apart in EWR, making using the RCC very inconvenient. (This dates back to when AC were partners with Continental and hence their gates are close to Con Air)