If a charge $Q$ is placed at the corner of a cube,what is the electric flux passing through one of its faces?

Let the electrostatic field $E$ at distance $r$ from a point charge $q$ not be an inverse square but instead an inverse cubic, e.g., $E = k \cdot \frac{q}{r^3} \hat{r}$, where $k$ is a constant.
Consider the following two statements:
$(I)$ Flux through a spherical surface enclosing the charge is $\phi = q_{\text{enclosed}} / \varepsilon_0$.
$(II)$ $A$ charge placed inside a uniformly charged shell will experience a force.
Which of the above statements are valid?

Assertion : Electric lines of force never cross each other.
Reason : Electric field at a point superimpose to give one resultant electric field.

When a $10 \mu C$ charge is enclosed by a closed surface,the flux passing through the surface is $\phi$. Now,another $10 \mu C$ charge is placed inside the closed surface,then the flux passing through the surface is . . . . . . .

Why do electric field lines not form closed loops?

The electric flux from a cube of edge $l$ is $\phi$ for an enclosed charge. If the edge of the cube is made $\frac{2}{3} l$ and the charge enclosed in the cube is doubled,then the electric flux value will be