Orienteering. Your local council may well have set a course up to introduce people to the sport.
1. Walk, run or bike.
2. You compete against yourself or others.
3. See 2.
4. Only a pair of trainers.
5. You have to navigate and calculate on the move.
6. Can be done in teams but usually alone.
7. Yes, could even be done in the dark.
8. You can set your own course therefor eyou decide the time.
9. See 5.
10. Bad weather = more challenge.
11. Not extremely popular but there are contacts.
12. Boring? You get out into varying terrain.
13. Your pace is up to you. You could walk and lessen the risk.
14. You are walking, running or biking. If you keep the food intake down you will lose weight.