What are the tiles of nobility?

They are the titles bestowed by a monarch and expressly forbidden by the US constitution. Although there are US citizens who covertly hold honorary British and European knighthoods etc.

It is best to remove the wall tiles. You need a flat service and a lot of times old tile will not be perfectly flat. If you remove the tiles you will have a good base to tile on. If you don't want to...

I have tiled over cork tiles with ceramic tiles and it worked fine in a bathroom, around a bath. If the current tiles are really well fixed it should be fine.

yes you can, but that doesn't mean that it's the best solution. the best way is to remove the old tile. period.

Yes you can. First are there any cracks in the floor? If so you need to put down an anti fracture membrane otherwise the new tile will just crack again. Second use a better quality thinset, one made...