Ground anchor foundation for cantilever umbrella 300x300

Hello everyone,

I would like to concrete in my cantilever umbrella.

I own a 300x300cm cantilever umbrella from a relatively well-known manufacturer brand in the mid-price segment. For these umbrellas, there are also suitable ground anchors, which I have ordered. A 40x40x40cm hole is recommended or "prescribed" for this.

Due to my installation situation (see attached pictures), I will not quite meet these dimensions.

From the raised edge of the terrace to the raised edge of the lawn, it is 40cm at the top edge - fits.
Due to the concrete wedge of the terrace edge, I only have 30cm at the very bottom.
The raised edge in the lawn is only laid on gravel.

Since I would rather not dig up the raised edge in the lawn and would have to remodel everything correctly in the end, I would like to keep it simple and place the anchor in my "intermediate bed" (according to the pictures).

Here are my questions:

1. Is it sufficient to concrete in a cantilever umbrella of this size with a hole of 30x40x40cm, or should I worry about stability?
2. Could I compensate for the 10 centimeters missing in width by increasing the length to 30x50x40cm? Would that help?
3. Does the position of the ground anchor affect stability if it is exactly centered, or can it also be placed more towards the lawn (as shown in the picture)?
4. Embedding electrical and water lines in concrete - should not be a problem, right?
5. I could theoretically place the anchor between the lines - this would put more tension or pressure on the lines - could that cause a problem?

I look forward to a brief input!

Thanks!