Hi,
1 - Could be a "Bell Tent". They were round with a central pole. Rather like a clock face, or a sliced pizza. Could house 8 to 12 men. A "Patrol type Tent" housed 6 to 8 men for the same ground area.
2 - It is a "Swagger Stick". Depending on the Regiment, it could be carried by Officers only, NCOs and above, or All Ranks. The idea was that you had to carry the stick and keep your hands out of your pockets.
3 - "Signaller", trained in semaphore signalling. Also was a messenger, so swift running was needed.
Regards
Chas