Thanks BMathews for all your explanation. Thank you all others for your kind advice.
I have to rely more on what the plan says than what experts on the field are saying.
They may be right, but as Mathews noted, they might not know what I have done before.

I put my foam back.

For instance, last night I measured the throw on the elevator and it was 1/2" while the plan says it should be 1/4" for a single rate radio. So I moved the clevis to a different hole. No wonder by just touching the elevator I almost stalled the plane on 2 occasions on take off.

The plane is now ready for my first solo landing and I am doing it this weekend.