PIC's serial receive peripheral questions
When the receive block is turned off the data stays in the buffer. If an overrun condition occurs the receiver will stop receiving. To get the receive block to start receiving again turn it off and turn it back on. 
The RCIF flag is set when there is at least one byte sitting in the buffer. 
The block does not multiply the clock by 16, instead it run at 16 times faster than the baud rate. This is to synchronize the incoming data because it is asynchronous.