Many Plugin shave been updated in the last few months so they would be compatible with v2014.
You should always install the latest versions into v2014.
Using an old version copied over from v2013 is a recipe for disaster and annoyance.
The SketchUcation PluginStore will have most of your Plugins - use the v2.6.0 feature to AutoInstall all of them using a My Setup 'Bundle'...
You need to have installed and opened v2.6.0 in v2013 - this will save a listing for that computer/version.
Then in v2014 your computer[s]/versions will be listed as 'Bundles'.
Duplicate the 13 'Bundle'.
Remove any Plugins you don't really want - you will have almost certainly have some installed you never use !
Remember to include the 'Libs' like tt's and LibFredo - otherwise many of their tools will not work without their Libs being installed.
Then simply AutoInstall that entire 'Bundle'...
Sit back while the list is processed - if you are installing into the default Plugins folder it should be surprisingly fast...
Remember that a few Extensions are only available from the ExtensionWarehouse - so you need to get/install those separately...
Remeber to restart SketchUp after adding all of these Plugins to complete the process - some recently installed Plugins [like Fredo's] will not work properly until SketchUp restarts...
So now your v2014 will have a similar setup of Plugins to v2013 - using all of the latest versions - of course there might be a few as yet incompatible ones around - but if so just Disable them in the SketchUcation PluginsManager and remember to let the author know about the issue - so it can be fixed asap...
If you have set up Sets under the PluginsManager in v2013, you can use the 'Export All Sets' option into a folder on your Desktop, then in v2014 use the PluginsManager Sets to 'Import Sets' to add the Sets from that folder - now v2013 and v2014 should look very familiar as you can choose which Plugins to Enable/Load/Disable for particular modeling tasks...