Q: iMac running slow with Mountain Lion

My 2007 iMac (4GB RAM) has Mountain Lion loaded (10.8.4).

Since loading its running very slow - 20-30 sec to login, more than 20 sec to open Firefox, etc.

Before I loaded ML I was told the system specs were adequate but i am wondering if I should go back to Snow Leopard.

Below some info on my system (having read a previous post on a related subject). I looked in Console and noticed a line repeating. I used to have a Lexmark printer a few months back, but removed that some time back (and also have had a new hard drive installed since and done a reinstall).

2013/08/30 8:55:47,756 PM com.apple.launchd.peruser.502[2228]: (com.lexmark.bmlaunchd[2636]) Exited with code: 1
2013/08/30 8:55:47,756 PM com.apple.launchd.peruser.502[2228]: (com.lexmark.bmlaunchd) Throttling respawn: Will start in 10 seconds

Hardware Information:

          iMac (20-inch, Mid 2007)

          iMac - model: iMac7,1

          1 2.4 GHz Intel Core 2 Duo CPU: 2 cores

          4 GB RAM

Video Information:

          ATI,RadeonHD2600 - VRAM: 256 MB

System Software:

          OS X 10.8.4 (12E55) - Uptime: 0 days 22:14:14

Disk Information:

          WDC WD5000AAKX-00ERMA0 disk0 : (500.11 GB)

                    disk0s1 (disk0s1) <not mounted>: 209.7 MB

                    Macintosh HD (disk0s2) /: 499.25 GB (408.55 GB free)

                    Recovery HD (disk0s3) <not mounted>: 650 MB

USB Information:

          Apple Inc. Built-in iSight

          Apple, Inc. Keyboard Hub

                    Apple Inc. Apple Keyboard

          Apple Inc. Bluetooth USB Host Controller

          Apple Computer, Inc. IR Receiver

FireWire Information:

Thunderbolt Information:

Kernel Extensions:

Problem System Launch Daemons:

Problem System Launch Agents:

          [failed] com.apple.accountsd.plist

          [failed] com.apple.coreservices.appleid.authentication.plist

          [failed] com.apple.pbs.plist

          [failed] com.apple.printtool.agent.plist

Launch Daemons:

          [failed] com.adobe.fpsaud.plist

          [loaded] com.google.keystone.daemon.plist

          [loaded] com.microsoft.office.licensing.helper.plist

          [loaded] com.trusteer.rooks.rooksd.plist

          [loaded] com.wdc.drivemanagerservice.plist

Launch Agents:

          [loaded] com.google.keystone.agent.plist

          [loaded] com.hp.messagecenter.launcher.plist

          [failed] com.lexmark.bmlaunchd.plist

          [failed] com.lexmark.lexnetlaunchd.plist

          [loaded] com.trusteer.rapport.rapportd.plist

User Launch Agents:

          [loaded] com.adobe.ARM.202f4087f2bbde52e3ac2df389f53a4f123223c9cc56a8fd83a6f7ae.plist

User Login Items:

          iTunesHelper

          AirPort Base Station Agent

          Google Drive

          Pinelands High School

          CNQL1213_ButtonManager

          ConnectService

          WDDriveManagerStatusMenu

3rd Party Preference Panes:

          Flash Player

          Flip4Mac WMV

          Rapport

Internet Plug-ins:

          AdobePDFViewer.plugin

          AdobePDFViewerNPAPI.plugin

          DirectorShockwave.plugin

          Flash Player.plugin

          FlashPlayer-10.6.plugin

          Flip4Mac WMV Plugin.plugin

          Google Earth Web Plug-in.plugin

          googletalkbrowserplugin.plugin

          iPhotoPhotocast.plugin

          JavaAppletPlugin.plugin

          npgtpo3dautoplugin.plugin

          o1dbrowserplugin.plugin

          OfficeLiveBrowserPlugin.plugin

          QuickTime Plugin.plugin

          SharePointBrowserPlugin.plugin

          Silverlight.plugin

User Internet Plug-ins:

Bad Fonts:

          None

Top Processes by CPU:

              77%          parentalcontrolsd

              72%          socketfilterfw

              23%          securityd

               8%          activitymonitord

               6%          Console

               2%          firefox

               2%          Shell

               2%          WindowServer

               1%          EtreCheck

               0%          Activity Monitor

Top Processes by Memory:

          229 MB   socketfilterfw

          217 MB   firefox

          121 MB   parentalcontrolsd

          102 MB   mds

          66 MB    Finder

          61 MB    WindowServer

          57 MB    Dock

          49 MB    Shell

          45 MB    rapportd

          43 MB    securityd

Virtual Memory Statistics

          1.25 GB  Free RAM

          1.86 GB  Active RAM

          429 MB   Inactive RAM

          487 MB   Wired RAM

          9.02 GB  Page-ins

          0 B      Page-outs