Can I fix my macbook or should I get a new one?

Question

Here are the problems I've been having.
My original account runs extremely slowly. After a little while on that account, my laoptop starts to make a noise that sounds like a ball dropping inside of the machine. I made another account because this one was slow. Note that although this was my first account on this macbook, I don't feel that I have a ton of saved things or extensive files. (and the macbook is 6, almost 7 years old, though I had the hard drive replaced a while ago.)
My second account isnt really slow, but its slower *sometimes* than my guest account. I have no real problems with my guest account, but Safari fails quite often. I have to quit the app and open it again once or a couple/few times to get back up to my ideal speed in loading pages.
I don't think my CD/DVD disk drive works. It hasnt worked for a long time though. When I put disks in, they dont play. (Side note, can they replace this?) Although, on one of the specs screens, it says that it does read DVD. So idk.
My battery life *****. I've replaced the battery before. I've also had bad luck with apple chargers. (the coating on the wires seems less durable than my oldest one, falls apart easily) I left for a vacation for a few days to a week and when I came back, my already poor battery life was nonexistent - since then, my computer wont work unless it is plugged into the charger. I'm not sure if this is the charger's fault or my battery/computer. However, now I have another problem. While charger is plugged in, lately my computer will go on standby even if I'm using it. I keep pushing keys so it will restore the screen. Then, shortly after that, the computer will shut down.  have to unplug and wiggle the charger around in the computer before it turns back on. Again, this could be the charger, right?
Aesthetcally, I'd want a new one. There are chips. The frame on the screen is coming off along the bottom and on the side a little bit. The keyboard is fine. It's the black one they dont make anymore. But we know macs arent cheap. (But I wont buy a "PC" laptop)
Please help me! Is there anyway to make my oldest account run fast, stop the ball dropping noise, get cds/dvds to work, and solve the non existent battery life? Or do you think I just need a new one?
Here are the basic specs:
Hardware Overview:
  Model Name: MacBook
  Model Identifier: MacBook4,1
  Processor Name: Intel Core 2 Duo
  Processor Speed: 2.4 GHz
  Number Of Processors: 1
  Total Number Of Cores: 2
  L2 Cache: 3 MB
  Memory: 4 GB
  Bus Speed: 800 MHz
  Boot ROM Version: MB41.00C1.B00
  SMC Version (system): 1.31f1
  Serial Number (system): W88271VC0P6
  Hardware UUID: 0E55A53C-68DA-550D-BAAD-F471FC27BD0E
  Sudden Motion Sensor:
  State: Enabled

Answer 1

Also...
One way to test is to Safe Boot from the HD, (holding Shift key down at bootup), run Disk Utility in Applications>Utilities, then highlight your drive, click on Repair Permissions, Test for problem in Safe Mode...
PS. Safe boot may stay on the gray radian for a long time, let it go, it's trying to repair the Hard Drive
Reboot, test again.
If it only does it in Regular Boot, then it could be some hardware problem like Video card, (Quartz is turned off in Safe Mode), or Airport, or some USB or Firewire device, or 3rd party add-on, Check System Preferences>Accounts (Users & Groups in later OSX versions)>Login Items window to see if it or something relevant is listed. Or an errant process eating up RAM.
Check the System Preferences>Other Row, for 3rd party Pref Panes.
Also look in these if they exist, some are invisible...
/private/var/run/StartupItems
/Library/StartupItems
/System/Library/StartupItems
/System/Library/LaunchDaemons
/Library/LaunchDaemons