(1) The cinema is 45 northeast of Xiaoming's home, 420 meters away from Xiaoming's home;

(2) The cinema is 30 northwest of the park and 630 meters away from the park;

(3) The shopping mall is 70 northeast of the park and 350 meters away from the park;

(4) The shopping mall is located 60 meters north of Naughty Bag and 360 meters away from Naughty Bag;

(5) The library is in the east of the naughty boy's house, 300 meters away from the naughty boy's house;

(6)420+630+350+360+300=2060 (meters),

2060÷60=25.75 (minutes),

25.75 minutes > 25 minutes,

A: Xiaoming's family has to walk 2060 meters to the library. If he walks 80 meters per minute, he can reach the library in 25 minutes.

So the answers are: (1) 45,420, (2) 30,630, (3) 70,350, (4) 60,360, (5) due east, 300.