Which layout is the best?

I wanna add faraday cage in my PCB.But my PCB has 2 layer.I used Top Layer(Red) for GND Plane.I used Bottom Layer(Blue) for Power and Data traces.

*My Questions:*

1-) If i create GND Plane on Bottom Layer(Blue) and add vias at around PCB.Is there any objection? (Look undermost image)

Emir,

This looks fine. What time of enclosure is this in? If it's metal you could also use that as a shield.

Nice little project. What tool did you use to lay this out?

I agree with Joe, that's a pretty good looking layout. But I'd go a different way. Rather than add ground, I'd flood that area with your VCC/VDD power, flooding over and eliminating most of those power traces. There are two advantages to this. It gives a lower impedance power distribution system, which lowers noise, and it adds a bit of capacitance between the power and ground fills. It's not much capacitance, but it's free and highly efficient at reducing high-frequency noise.

It appears that you have an ESD ground ring around the board edge. I'd double that up with ground on the opposite layer as well and add vias stitching them together around the edge.

Thank you Joe and Gary.Thank you for your comments.

and Mr.Crowell i will apply your idea(double ESD ring) for my layout

Last few years I am on a trying to search several PCB
manufacturing international company in the world. Many of them found but
confused their quality and quantity because it seems to be like good. Usually
I'm working with 4 and 6 layers PCB. 4
layer needs to solved photoluminescence and Electroluminescence, Luminescent
efficiency.