In my opinion tallness of mountains is quite relative in both actual height and the level of difficulty of ascent, but at least 3000 meters and more than a weeks ascent should prove sufficient. Being atop of Olympus Mons would be perfect though.

Apatheism would probably be an even better outcome, sadly in the following thousand or so years it could take root as the main spiritual stance only if most of mankind was eradicated as some concept of deity seems to be necessary for most. Making people doubt their beliefs or turn away from the concept of one, distinguishable, sentient god would be the best first step. I myself, usually take the "I don't care because there is neither a way nor a benefit of knowing" stance.

I have a rational fear of radiation - I am not scared of decayed plutonium samples, but I dislike taking X-Rays before determining how many millisieverts I'll receive and I abstain from going in the sun without heavy sunscreen, because lets face it - DNA damage is not fun. But as I said - it wouldn't be hard to leave it behind if I got a chance to, for example, work at CERN or be abroad a manned space shuttle. Geiger counter is one of my to-buy things and I still have a fallout map stashed somewhere, just in case though.

Uploading... It actually depends. If it's on the lines of becoming a sentient, cybernetic organism (e.g. development of cyberbrain as in some science-fiction franchises) , I would probably be first in line. For all other types of mind-uploading sentience would be the first perquisite and singular or conscious parallel existence the second.

And you are quite welcome.