\[\boxed{\mathbf{458}.}\]
\[1)\ \frac{\sqrt[3]{7} \bullet \sqrt[4]{343}}{\sqrt[12]{7}} = \frac{\sqrt[{3 \bullet 4}]{7^{4}} \bullet \sqrt[{4 \bullet 3}]{343^{3}}}{\sqrt[12]{7}} =\]
\[= \frac{\sqrt[12]{7^{4}} \bullet \sqrt[12]{\left( 7^{3} \right)^{3}}}{\sqrt[12]{7}} =\]
\[= \sqrt[12]{\frac{7^{4} \bullet 7^{9}}{7}} = \sqrt[12]{7^{12}} = 7;\]
\[2)\ \left( \sqrt[3]{9} + \sqrt[3]{6} + \sqrt[3]{4} \right)\left( \sqrt[3]{3} - \sqrt[3]{2} \right) =\]
\[= \sqrt[3]{9 \bullet 3} - \sqrt[3]{9 \bullet 2} + \sqrt[3]{6 \bullet 3} -\]
\[- \sqrt[3]{6 \bullet 2} + \sqrt[3]{4 \bullet 3} - \sqrt[3]{4 \bullet 2} =\]
\[= \sqrt[3]{3^{2} \bullet 3} - \sqrt[3]{18} + \sqrt[3]{18} -\]
\[- \sqrt[3]{12} + \sqrt[3]{12} - \sqrt[3]{2^{2} \bullet 2} =\]
\[= \sqrt[3]{3^{3}} - \sqrt[3]{2^{3}} = 3 - 2 = 1.\]