1)
It's a nominalizer, changing a verb into a noun just like gerund in English (look --> looking).
2)
typo: hashitteimasu
"3kiro" is not the location of transfer. It's just not mentioned in that sentence (e.g. dōro wo 3kiro hashitteimasu). However, "3kiro wo hashiru" is also used. In this case, "3kiro" often refers to a purpose or represents a location of 3 kilometers length.
Sure.