Mac crashing more and more frequently since Mavericks - Why?

Question

My MacBook Pro has been crashing frequently since Mavericks - just freezing up, no keyboard or mousepad reaction -  and it is incompatible with software I rely on, such as older versions of Endnote. Also little things are delayed, such as the file and folder view - the window is blank for a long time before the folders appear, etc. 
The software I was running when it crashed included, though not all at once, and not every time: Word, Flash, iTunes, iCal, Safari, Wifi on or off - no difference, Endnote 7, Zotero and/or Mendeley (the latter three which I only installed to find a solution to the Endnote problem).  I only have the one [internal] montior, no external drives, and my settings are all pretty basic.  No Keylogger or anything like that - I'm the only user. 
Apple were not really able to help, nor did they seem to think there was an Apple-wide problem; he said he had never heard of Mavericks and crashing troubles?!?!?!  My IT guy at work had no clue.  Can anyone please, please help me?
I have lost so much work time trying to sort this out and rebooting after crashes, and am thoroughly dismayed; I have used Macs since the 80s and this is the first time one has ever, ever crashed on me.  My laptop is not reliable anymore.
Many thanks

Answer 1

Thanks so much, arthur.  I did an EtreCheck and it is below:
Hardware Information:
          MacBook Pro - model: MacBookPro10,1
          1 2.3 GHz Intel Core i7 CPU: 4 cores
          8 GB RAM
Video Information:
          Intel HD Graphics 4000 - VRAM: 1024 MB
          NVIDIA GeForce GT 650M - VRAM: 1024 MB
Audio Plug-ins:
          BluetoothAudioPlugIn: Version: 1.0 - SDK 10.9
          AirPlay: Version: 1.9 - SDK 10.9
          AppleAVBAudio: Version: 2.0.0 - SDK 10.9
          iSightAudio: Version: 7.7.3 - SDK 10.9
System Software:
          OS X 10.9 (13A603) - Uptime: 0 days 0:5:0
Disk Information:
          APPLE SSD SM256E disk0 : (251 GB)
                    EFI (disk0s1) <not mounted>: 209.7 MB
                    Macintosh HD (disk0s2) /: 250.14 GB (146.17 GB free)
                    Recovery HD (disk0s3) <not mounted>: 650 MB
USB Information:
          Apple Inc. FaceTime HD Camera (Built-in)
          Apple Inc. Apple Internal Keyboard / Trackpad
          Apple Inc. BRCM20702 Hub
                    Apple Inc. Bluetooth USB Host Controller
FireWire Information:
Thunderbolt Information:
          Apple Inc. thunderbolt_bus
Kernel Extensions:
          se.coolbook.driver2          (2.0.9)
Problem System Launch Daemons:
Problem System Launch Agents:
Launch Daemons:
          [loaded] com.adobe.fpsaud.plist
          [loaded] com.oracle.java.Helper-Tool.plist
Launch Agents:
          [loaded] com.divx.dms.agent.plist
          [loaded] com.divx.update.agent.plist
          [loaded] com.oracle.java.Java-Updater.plist
User Launch Agents:
          [loaded] com.divx.agent.postinstall.plist
          [loaded] com.google.keystone.agent.plist
User Login Items:
          iTunesHelper
3rd Party Preference Panes:
          Flash Player
          Flip4Mac WMV
          Java
Internet Plug-ins::
          Google Earth Web Plug-in: Version: 5.2
          Default Browser: Version: 537 - SDK 10.9
          Flip4Mac WMV Plugin: Version: 3.1.0.24   - SDK 10.8
          AmazonMP3DownloaderPlugin1016264: Version: Unknown
          OfficeLiveBrowserPlugin: Version: 12.3.6
          OVSHelper: Version: 1.1
          FlashPlayer-10.6: Version: 11.9.900.152 - SDK 10.6
          DivXBrowserPlugin: Version: 2.2
          AmazonMP3DownloaderPlugin101749: Version: Unknown
          Flash Player: Version: 11.9.900.152 - SDK 10.6 Outdated! Update
          iPhotoPhotocast: Version: 7.0
          QuickTime Plugin: Version: 7.7.3
          RealPlayer Plugin: Version: Unknown
          Silverlight: Version: 5.1.10411.0 - SDK 10.6
          Unity Web Player: Version: UnityPlayer version 2.5.5f1
          JavaAppletPlugin: Version: Java 7 Update 21 Outdated! Update
User Internet Plug-ins::
          AddLive: Version: AddLive 2.1.6.1
Bad Fonts:
          None
Old applications:
          Keynote:          Version: 5.3 - SDK 10.5
                    /Applications/iWork '09/Keynote.app
          Microsoft AutoUpdate:          Version: 2.3.6 - SDK 10.4
                    /Library/Application Support/Microsoft/MAU2.0/Microsoft AutoUpdate.app
          Microsoft Error Reporting:          Version: 2.2.9 - SDK 10.4
                    /Library/Application Support/Microsoft/MERP2.0/Microsoft Error Reporting.app
          Microsoft Ship Asserts:          Version: 1.1.4 - SDK 10.4
                    /Library/Application Support/Microsoft/MERP2.0/Microsoft Ship Asserts.app
          Pages:          Version: 4.3 - SDK 10.5
                    /Applications/iWork '09/Pages.app
          SLLauncher:          Version: 1.0 - SDK 10.5
                    /Library/Application Support/Microsoft/Silverlight/OutOfBrowser/SLLauncher.app
Time Machine:
          Skip System Files: NO
          Mobile backups: OFF
          Auto backup: NO
          Volumes being backed up:
                    Macintosh HD: Disk size: 232.96 GB Disk used: 96.83 GB
          Destinations:
                    Iomega_HDD [Local] (Last used)
                    Total size: 465.64 GB
                    Total number of backups: 5
                    Oldest backup: 2012-10-15 22:22:44 +0000
                    Last backup: 2013-09-01 15:35:36 +0000
                    Size of backup disk: Adequate
                              Backup size 465.64 GB > (Disk used 96.83 GB X 3)
          Time Machine details may not be accurate.
          All volumes being backed up may not be listed.
Top Processes by CPU:
              25%          JL Edwardian Advent Calendar
               7%          CalendarAgent
               7%          WindowServer
               4%          EtreCheck
               1%          hidd
Top Processes by Memory:
          115 MB          com.apple.IconServicesAgent
          98 MB          mds_stores
          82 MB          Dock
          57 MB          JL Edwardian Advent Calendar
          57 MB          WindowServer
Virtual Memory Statistics:
          5.62 GB          Free RAM
          1.31 GB          Active RAM
          190 MB          Inactive RAM
          897 MB          Wired RAM
          238 MB          Page-ins
          0 B          Page-outs