According to Gauss law of electrostatics, electric flux through a closed surface depends on:

According to Gauss Law of electrostatics electric flux through a closed surface is given by, Flux $=\text{∮}\overrightarrow{\mathrm{E}}\cdot \mathrm{d}\overrightarrow{\mathrm{s}}=\frac{{\mathrm{q}}_{\mathrm{en}}}{{\mathrm{ϵ}}_0}$

Clearly, fl ux is directly proportional to charges enclosed by the surface.
(1) Qualitatively, fl ux is defined as number of field lines crossing the surface area perpendicularly.

Even for a bigger area same number of field lines are crossing. Thus, flux do not depend on area of closed surface.

(3) and (4)

The electric field and angle between $\overrightarrow{\mathrm{E} }\text{and }\mathrm{d}\overrightarrow{\mathrm{s}}$
will compensate each other in such a way that, flux will only depend on enclosed charge.