re: Today is the 50th Anniversary of the Apollo 1 fire

That was one of the bigger "what ifs" in the history of the American space program. Grissom was 100% going to be the commander of the first landing. Ed White would've no doubt commanded a landing mission, too. However, that first command module was a lemon and had a colossal number of issues. I believe it was Frank Borman who said that if the fire hadn't happened and led to a rework of the CM, they probably would've lost a crew in space at a later date.

I highly suggest anyone go read Andrew Chaikin's book A Man On The Moon. It's probably the definitive work on the inner workings of the Apollo program, and gives a mission-by-mission account via the astronauts' own words.