If I get to go with a Tardis, language barrier won’t be a problem. If not, medieval Europe will be out of the question, since languages have changed so much during the past few centuries.
If you travel back even further to see mammoths or even dinosaurs, languages won’t be an issue. Who knows what the ancient microbes will do to your immune system, so there are some serious risks.
I guess the past 200 years might be the most reasonable ones to choose from. I think I might want to meet James Prescott Joule (1818-1889), the inventor of the correct unit of energy.
James Watt (1736-1819) would be pretty interesting too, so I hope English hasn’t changed too much. Would be pretty annoying if I were can’t communicate properly.
Yes, you’re crazy. Stainless steel won’t last a million years. Not even close. You should go with titanium instead. That would also create a massive density difference between the two pieces in case someone lifts them up separately. Feeling the weight difference of the two pieces is very confusing for most people.