Ok, so yesterday I was changing the strings on my acoustic (a low end Samick). It needed a thorough cleaning, so I removed all of the strings and cleaned it well before replacing them. I'm thinking that was a mistake...

First, when I was polishing the back of the guitar, the saddle fell out. I've since read that it's supposed to 'float', i.e., it's not glued in. But is it supposed to be that loose? Temporarily, I've set it back in the bridge and put strings on, pending repairs if I need them.

Next, I put the new strings on, and now the tuners seem to be loose, because they buzz when I pluck the low E or the G strings. Is there an easy way to fix this, or is it for the luthier?

Finally, I'm using D'dario strings, 0.12 guage. They've apperently replaced their old colour coduing system with a more environmentally sound scheme that is bronze-silver-black-bronze-silver-black, whic is fine. But when I replaced the high E string and stetched/tuned it, the ball at the end of it came unwound, and the string pulled out of the bridge. I replaced it with a second e string, and the same thing happened. Has this happened to anyone else? I'm thinking I'm either extremely unlucky, or it's a poorly constructed string...which would be odd, because I've used them for a while, and never had any trouble.

Anyway, long stroy short, is it worth getting this repaired, or would it cost enough to warrent just getting a new guitar?
"He has a woman's name and wears makeup. How original."
--Alice Cooper, on Marilyn Manson.
that used to happen to me using d'darios, just take it slow tuning it and loosen it by bending in a lower tuning
The string was bad. It's one of those things that happens even with good strings. Just go to the music shop and tell them what happened and they should give you a new string.

bridge thing is normal and you did the right thing. Just put it back in, no repair needed. It shouldn't happen on a high end guitar but you have a low end sammic so...

The rattle could be caused by a couple things. Most guitars come stock with 11's now days. If you guitar had 11's and you put 12's on it then the rattle could be from a loose truss rod vibrating within the neck. Or it could be that your tuners are loose, like you said. If you look at the peghead of the guitar you will see that around the tuning pegs is a bolt. Tighten the bolt on the strings that rattle. If they still rattle then tighten your truss rod about 1/4 turn.

You didn't do anything wrong. So far you have done everything right and the problems that you are having are normal.
Not taking any online orders.
Sounds great...thanks all. It's not a great instrument, but I've completely fallen in love with it, so I don't want to have to get rid of it. Good to hear that this is all par for the course. And about the strings, this'll give me an opportunity to try a different brand, I've never used anything but D'Adarrio's. Thanks!
"He has a woman's name and wears makeup. How original."
--Alice Cooper, on Marilyn Manson.