Translate every condition into an equation and retain exact values throughout the hyperbola calculation.
\[\begin{aligned}49y^2-16x^2 &= 784\Rightarrow\frac{y^2}{16}-\frac{x^2}{49}\\&= 1\end{aligned}\]
\[\begin{aligned}a &= 4,b\\&= 7,c\\&= \sqrt{65}\end{aligned}\]
\[\begin{aligned}c^2 &= a^2+b^2,\quad e\\&= \frac ca,\quad\ell\\&= \frac{2b^2}{a}\end{aligned}\]
\[\begin{aligned}F &= (0,\pm\sqrt{65}),\ V\\&= (0,\pm4),\ e\\&= \frac{\sqrt{65}}4,\ \ell\\&= \frac{49}{2}\end{aligned}\]
The last line satisfies the original conditions and supplies every requested part.
Final answer\[F=(0,\pm\sqrt{65}),\ V=(0,\pm4),\ e=\frac{\sqrt{65}}4,\ \ell=\frac{49}{2}\]