Ok, ur first question is:
When EA is tied high, then both internal AND external code memories are available, lower 8K bytes being on-chip. Above this 8K (range 0x0-0x1fff), external memory is accessed. When the Program counter points to the first location of external memory, WHAT address is output on the address lines? is it 0x0 ? or is it 0x2000 ?
A: it is 0x2000

and second:
Same question is for the external data memory. After 256 bytes (first 256 bytes accessed on-chip), the external data memory is accessed. What address would be output for the first address of external data memory? is it 0x0 or is it 0x100 ?

here there is some misunderstanding to u. the internal 256 bytes is NOT a part of the 64K data memory. it is only RAM used for storing temporary data during program execution. so the first location of external data memory will always be 0x0000. It is not at all concerned with the 256 bytes RAM.
right??