Again, I don’t mean to be too critical of your attempts, but you have posted various different solutions in a relatively short amount of time, which leads me to conclude that your method is non-deterministic, i.e. that it is speculative. All theories are welcome, but:
None of your solutions contain BERLIN in the place it should be.
None of your proposed solutions make any sense.
K4 is, as Sanborn described, “the apex of the pyramid”, which in my interpretation means it is the pinnacle of the Kryptos puzzle, and therefore is the conclusion to the plaintext of the previously deciphered first three parts. He has also said that there is a, shall we say, “K5″ which cannot be solved without K1-K4. K4 has to be readable, meaningful, and related to K1-K3 in a holistic way.
Given the title of the sculpture, what does “T is your position” mean to you?