Hint Getting money
Go to the fountain and use "Telepathy". An old man will appear and will act like an ATM machine.
Finding the air gun
The air gun for the weakling is in Youngtown. Go to the empty church, and start moving north-east. You will see a little kid, keep moving to find two buildings. One is a hotel and the other is a general store. Enter the store and buy the air gun for 1200 dollars.
Finding Ego Orb
Search in the lost underworld near the fire spring. You may have to do a lot of walking to locate him.
Finding the broken antenna
It is located in the Tenda village in the junk yard.
Unlimited magic butterflies
Go to the cave in Onett and find the location where you can see the giant step but cannot get to it. Keep entering and exiting this location, heal yourself, then get more butterflies as needed.