I agree -- it is hard to find where to click to close the current tab -- I often end up using the keyboard accelerator (Ctrl-Q or Ctrl-W -- I forget offhand). It's not very user-friendly in that regard.
Better, would be an option to move the 'close-X' icon to a fixed location, like at the far right of the tab-bar like firefox or palemoon have. You can the close-X icon to the far right so it always allows you to close the current tab by clicking it. Often which tab is active is hard to see -- especially if you have multiple tabs open.
This should really be considered an "accessibility" option.
