#1
Despite playing for about 5 years now, I've never changed the strings on any of my guitars because I was too lazy to and it seemed tedious.

Lo and behold, my first time re-stringing my though body guitar and the little metal piece the string is fed through on the front popped out of the damn wood when I removed the old string. Tried putting it back, but it won't stay in. Is this normal, or is it broken? If I stick it back in and put the new sting on, is going to just pop out of there or what?
#2
Get some super glue, put it on the sides of the little thingy, called a ferrule by the way, and stick it in the hole. Hold it there for a few minutes, and it'll stay put.

My things:
Bowes SLx7
Washburn WG587
Washburn X40Pro
Washburn X50
Washburn HM24
Washburn WR150
Laguna LE200s
Arietta Acoustic
First Act
Valveking 112
VHT Deliverance

#3
Set it with a wood-to-metal adhesive and stick it back in. Whatever you do, DON'T try to restring without it. A friend of mine (bit of a n00b) did that and his string that was missing the ferrule cut a groove into the body of the guitar. Those little suckers are important.
ESP/LTD F-50
1989 Kramer Showster
Rogue RADH Acoustic
Fender CD-60 Acoustic
Washburn XB-100 4 string
Peavey Millenium AC BXP
Fender Rumble 150
Crate BV60H Head
Crate BV412 Cab
Vox AD15VT