My 2011 Mac intermittently runs slowly, not as snappy as it originally was. Rainbow wheel much more frequently. Wondering if there are any fixes? Thanks

Question

This is my Etresoft info:
Problem description:
Mac 2011 runs slow intermittently. Rainbow wheel etc.
EtreCheck version: 2.1.6 (109)
Report generated January 19, 2015 at 7:26:06 PM CST
Download EtreCheck from http://etresoft.com/etrecheck
Click the [Support] links for help with non-Apple products.
Click the [Details] links for more information about that line.
Click the [Adware] links for help removing adware.
Hardware Information: ℹ️
  iMac (21.5-inch, Mid 2011) (Technical Specifications)
  iMac - model: iMac12,1
  1 2.5 GHz Intel Core i5 CPU: 4-core
  4 GB RAM Upgradeable
  BANK 0/DIMM0
  2 GB DDR3 1333 MHz ok
  BANK 1/DIMM0
  2 GB DDR3 1333 MHz ok
  BANK 0/DIMM1
  empty empty empty empty
  BANK 1/DIMM1
  empty empty empty empty
  Bluetooth: Old - Handoff/Airdrop2 not supported
  Wireless:  en1: 802.11 a/b/g/n
Video Information: ℹ️
  AMD Radeon HD 6750M - VRAM: 512 MB
  iMac 1920 x 1080
System Software: ℹ️
  OS X 10.10.1 (14B25) - Time since boot: 2 days 8:49:40
Disk Information: ℹ️
  WDC WD5000AAKS-402AA0 disk0 : (500.11 GB)
  EFI (disk0s1) <not mounted> : 210 MB
  Macintosh HD (disk0s2) / : 499.25 GB (259.10 GB free)
  Recovery HD (disk0s3) <not mounted>  [Recovery]: 650 MB
  OPTIARC DVD RW AD-5690H 
USB Information: ℹ️
  Apple Internal Memory Card Reader
  Apple Computer, Inc. IR Receiver
  Apple Inc. FaceTime HD Camera (Built-in)
  Fitbit Inc. Fitbit Base Station
  Apple Inc. BRCM2046 Hub
  Apple Inc. Bluetooth USB Host Controller
Thunderbolt Information: ℹ️
  Apple Inc. thunderbolt_bus
Gatekeeper: ℹ️
  Mac App Store and identified developers
Kernel Extensions: ℹ️
  /System/Library/Extensions
  [not loaded] com.elgato.driver.DontMatchAfaTech (1.1) [Support]
  [not loaded] com.elgato.driver.DontMatchCinergy450 (1.1) [Support]
  [not loaded] com.elgato.driver.DontMatchCinergyXS (1.1) [Support]
  [not loaded] com.elgato.driver.DontMatchEmpia (1.1) [Support]
  [not loaded] com.elgato.driver.DontMatchVoyager (1.1) [Support]
Launch Agents: ℹ️
  [running] com.hp.devicemonitor.plist [Support]
  [loaded] com.hp.messagecenter.launcher.plist [Support]
  [running] com.teamviewer.teamviewer.plist [Support]
  [running] com.teamviewer.teamviewer_desktop.plist [Support]
Launch Daemons: ℹ️
  [loaded] com.adobe.fpsaud.plist [Support]
  [running] com.elgato.EyeConnect.plist [Support]
  [running] com.fitbit.fitbitd.plist [Support]
  [running] com.fitbit.galileod.plist [Support]
  [loaded] com.teamviewer.Helper.plist [Support]
  [running] com.teamviewer.teamviewer_service.plist [Support]
User Launch Agents: ℹ️
  [loaded] com.google.keystone.agent.plist [Support]
User Login Items: ℹ️
  Garmin Express Service Application  (/Applications/Garmin Express.app/Contents/Library/LoginItems/Garmin Express Service.app)
  EyeTV Helper Application Hidden (/Library/Application Support/EyeTV/EyeTV Helper.app)
  Canon IJ Network Scan Utility Application  (/Library/Printers/Canon/BJPrinter/Utilities/Canon IJ Network Scan Utility.app)
  iTunesHelper Application Hidden (/Applications/iTunes.app/Contents/MacOS/iTunesHelper.app)
  Fitbit Connect Menubar Helper Application  (/Applications/Fitbit Connect.app/Contents/MacOS/Fitbit Connect Menubar Helper.app)
Internet Plug-ins: ℹ️
  Flip4Mac WMV Plugin: Version: 2.3.8.1 [Support]
  FlashPlayer-10.6: Version: 16.0.0.257 - SDK 10.6 [Support]
  Default Browser: Version: 600 - SDK 10.10
  Flash Player: Version: 16.0.0.257 - SDK 10.6 [Support]
  LogMeIn: Version: 1.0.961 - SDK 10.7 [Support]
  QuickTime Plugin: Version: 7.7.3
  LogMeInSafari32: Version: 1.0.961 - SDK 10.7 [Support]
  GarminGpsControl: Version: 4.0.4.0 Release - SDK 10.6 [Support]
  Silverlight: Version: 5.1.10411.0 - SDK 10.6 [Support]
Safari Extensions: ℹ️
  AdBlock [Installed]
  Ghostery [Installed]
  Twitter for Safari [Installed]
  1-ClickWeather [Installed]
3rd Party Preference Panes: ℹ️
  Flash Player  [Support]
  Flip4Mac WMV  [Support]
Time Machine: ℹ️
  Skip System Files: NO
  Auto backup: YES
  Volumes being backed up:
  Macintosh HD: Disk size: 499.25 GB Disk used: 240.15 GB
  Destinations:
  Data [Network]
  Total size: 2.00 TB
  Total number of backups: 144
  Oldest backup: 2012-03-10 14:26:42 +0000
  Last backup: 2015-01-20 00:43:03 +0000
  Size of backup disk: Excellent
  Backup size 2.00 TB > (Disk size 499.25 GB X 3)
Top Processes by CPU: ℹ️
      4% mds
      2% WindowServer
      0% HP Device Monitor
      0% Fitbit Connect Menubar Helper
      0% AppleSpell
Top Processes by Memory: ℹ️
  408 MB iPhoto
  266 MB firefox
  146 MB com.apple.WebKit.WebContent
  129 MB Safari
  77 MB softwareupdated
Virtual Memory Information: ℹ️
  62 MB Free RAM
  1.55 GB Active RAM
  1.50 GB Inactive RAM
  895 MB Wired RAM
  19.22 GB Page-ins
  227 MB Page-outs
Diagnostics Information: ℹ️
  Jan 17, 2015, 06:13:40 PM /Users/[redacted]/Library/Logs/DiagnosticReports/plugin-container_2015-01-17-18 1340_[redacted].crash
  Jan 17, 2015, 10:37:03 AM Self test - passed

Answer 1

When you see the beachball cursor, note the exact time: hour, minute, second.  
These instructions must be carried out as an administrator. If you have only one user account, you are the administrator.
Launch the Console application in any of the following ways:
☞ Enter the first few letters of its name into a Spotlight search. Select it in the results (it should be at the top.)
☞ In the Finder, select Go ▹ Utilities from the menu bar, or press the key combination shift-command-U. The application is in the folder that opens.
☞ Open LaunchPad and start typing the name.
The title of the Console window should be All Messages. If it isn't, select
          SYSTEM LOG QUERIES ▹ All Messages
from the log list on the left. If you don't see that list, select
          View ▹ Show Log List
from the menu bar at the top of the screen.
Each message in the log begins with the date and time when it was entered. Scroll back to the time you noted above.
Select the messages entered from then until the end of the episode, or until they start to repeat, whichever comes first.
Copy the messages to the Clipboard by pressing the key combination command-C. Paste into a reply to this message by pressing command-V.
The log contains a vast amount of information, almost all of it useless for solving any particular problem. When posting a log extract, be selective. A few dozen lines are almost always more than enough.
Please don't indiscriminately dump thousands of lines from the log into this discussion.
Please don't post screenshots of log messages—post the text.
Some private information, such as your name, may appear in the log. Anonymize before posting.