You can easily select meshes in the menus at the bottom and 10,000 is just a number I snatched out of thin air. Size limit is 102,400 units, coordinate limit is unknown but well over 100,000 units perhaps only limited by memory. If you haven't already I suggest reading the manual to learn the controls. If you don't like Bryce then why do you use it? Personally I don't like 3DSMax or LW, Maya is ok because it's very similar to Bryce.