If you have permission AND it is a PRIVATE airfield. I believe that all airfields under the jurisdiction of the Federal Aviation Administration (FAA) require a special license to operate a vehicle on an active airfield.
No
No.
no
no
A learner driver has the same speed restrictions as any other road user.
Learner's licences in Namibia are like learner's licences in any other country - you're not permitted to drive without being supervised by a fully licenced driver.
You must be insured to drive a vehicle no matter what your age or if you have a learner's permit or regular license. You must be covered under a policy.
no
no
parent or legal guardian
No No
Yes it is fine.