Both of these are excellent points. Regarding military war games, what I had in mind is that the rules should be realistic (to maximize the number of possible strategies) while still being difficult or impossible to game; neither of which seems to be the case for military war games as they are currently played. This might entail (as in HPMoR!Quirrell's war games) that there should be no formal rules at all but a judge to decide who had won by practical real-world standards, but this would probably severely limit the popularity of the sport.
I have not played airsoft and so was unaware of these safety measures. What are the risks and rates of injury after accounting for common safety practices? It seems like the only other dangers would be those common to all sports involving running around in rough terrain. Assuming there are rules in place for players being eliminated from the game once they are shot (and not being allowed to give information to team members about enemy positions, etc.) this seems like the perfect rationalist sport.
Although the games themselves do not involve much physical activity compared to other sports, a lot of professional RTS players (Starcraft, League of Legends, etc.) end up on surprisingly strenuous exercise regiments to improve their reflexes and hand-eye coordination and gain the physical benefits mentioned (Cardiovascular benefits, muscle development, coordination and control over muscles) as a side-effect of preparing to compete at a professional level.
Certain kinds of war games might also qualify as a rationalist sport if they were modified a bit. If military war games were made less fake, airsoft and paintball made less dangerous, and laser tag made more realistic they would each meet all of these desiderata.
Does anyone have advice for effective learning in distracting/suboptimal environments? I know LW recommends textbooks and learning by accumulation instead of random walks, but I have at most 1-2 hours of uninterrupted time per day I can spend learning optimally vs. 8+ hours per day I could potentially use to learn sub-optimally (e.g. frequent distractions, sudden interruptions, hours between learning sessions) during downtime at work that is currently going to waste. Are there better formats than textbooks for these environments or would it be more effective to divide textbook material into sequences of micro-learning sessions? If so, how does one organize and divide this material for effective self-study? If not, are there other ways to effectively spend this time towards incremental self-improvement?