We cannot estimate anything, because we just have too little information about ET life. We cannot even accurately estimate how long any given life form has exi

We cannot estimate anything, because we just have too little information about ET life. We cannot even accurately estimate how long any given life form has existed. For example, Earth is relatively young planet, and exists planets which are Billion years older. And according to Turing theorem, we could only understand life form similarly developed or less developed than our. So, if we will encounter similarly developed or less developed life form (younger than our), we could make decision what to do with it. But if we will encounter much older life form, I think limit is just about few hundred years difference, we just will not understand them, may be even they will look like natural phenomena or super-natural as gods. And when we will encounter less developed ETs, we cannot be sure, that nearby not hidden much more developed ETs, which could wipe us. So I think, safest for us will be to avoid any interaction and research them with remote sense technologies.