Ok thats good
# 2 I would say once a week but could be left for 2 weeks
# 1 I Don't know I have never used tractors But lm looking into them for the chicks I'm getting in the spring
Depending on where you are located you probably Will need to check your government policies to check how many your allowed to have without Getting your chicken farming license thing.
Where I am I can only have 99 chickens without getting one\
You should look into that before doing this math...