1) If I change any connection or component in the layout then it should show the error indicating that it is not in schematic.
Since you cannot change the connectivity, or the footprint component in PCB Editor, there is nothing to show in the schematic. If you make an invalid connection you will get a DRC in PCB Editor. The connectivity and footprints are determined from the netlist and this gets generated from the schematic data.
2) Some times i may forget some connections in the schematic. In such case if I add any new connection in the layout then it should be applied to the schematic.
The exact same thing applies, you cannot add, or remove connections in PCB Editor so, again, there is nothing to show in the schematic.
This question seems to be "pretty much" like the previous question and, strangely, the answer remains "pretty much" the same!