No media-search results in Sitecore8 with Solr 5.3.1 and Brightcove

Question

I have a working Sitecore 8 solution with Solr 5.3.1 for content search. Indexes work, are updated as expected on publish etc.

Now we are about to add Brightcove, but installing the brightcove package adds a Lucene index to the App_config/include folder, which makes the search api fail. I have overcome this problem by finding a custom config (Sitecore Support seems to have constructed this config as a substitute for the lucene counterpart)

Sitecore.Support.ContenteSearch.MediaFramework.Brightcove.SOLR.config

from this website (https://grantkillian.wordpress.com/tag/solr/).

This solution only seems to work partially with Sitecore 8.0 and SOLR 5.3.1.

The problem with the above link and description is that it contains a configuration-section that adds three copy-fields, which the sitecore log complains about; configuration section: __yourtags __created __updated Log file error if the above section is contained in the
Sitecore.Support.ContenteSearch.MediaFramework.Brightcove.SOLR.config:

Message: Could not find add method: AddCopyField (type: Sitecore.ContentSearch.SolrProvider.SolrIndexConfiguration)
Source: Sitecore.Kernel
   at Sitecore.Configuration.Factory.AssignProperties(Object obj, Object[] properties)
   at Sitecore.Configuration.Factory.AssignProperties(XmlNode configNode, String[] parameters, Object obj, Boolean assert, Boolean deferred, IFactoryHelper helper)
   at Sitecore.Configuration.Factory.CreateObject(XmlNode configNode, String[] parameters, Boolean assert, IFactoryHelper helper)
   at Sitecore.Configuration.Factory.GetInnerObject(XmlNode paramNode, String[] parameters, Boolean assert)
   at Sitecore.Configuration.Factory.AssignProperties(XmlNode configNode, String[] parameters, Object obj, Boolean assert, Boolean deferred, IFactoryHelper helper)
   at Sitecore.Configuration.Factory.CreateObject(XmlNode configNode, String[] parameters, Boolean assert, IFactoryHelper helper)
   at Sitecore.Configuration.Factory.GetInnerObject(XmlNode paramNode, String[] parameters, Boolean assert)
   at Sitecore.Configuration.Factory.AssignProperties(XmlNode configNode, String[] parameters, Object obj, Boolean assert, Boolean deferred, IFactoryHelper helper)
   at Sitecore.Configuration.Factory.CreateObject(XmlNode configNode, String[] parameters, Boolean assert, IFactoryHelper helper)
   at Sitecore.Configuration.Factory.CreateObject(String configPath, String[] parameters, Boolean assert)
   at Sitecore.ContentSearch.ContentSearchManager.get_SearchConfiguration()
   at Sitecore.ContentSearch.SolrProvider.SolrContentSearchManager.get_Cores()
   at Sitecore.ContentSearch.SolrProvider.CastleWindsorIntegration.WindsorSolrStartUp.Initialize()
   at CustomSolution\Global.asax.cs:line xx

If I choose to comment out the above configuration section I end up with the following error messages in my Search.log:

7352 12:52:56 ERROR Solr Error : ["org.apache.solr.search.SyntaxError: Cannot parse '(((__smallupdateddate_tdt:[0001-01-01T00:00:00Z TO *] AND __smallupdateddate_tdt:[* TO 9999-12-31T23:59:59Z}) AND __is_running_b:(True)) AND datasourceitems_t:(*{3D6658D8-A0BF-4E75-B3E2-D050FABCF4E1}*))': Encountered " "}" "} "" at line 1, column 198.
Was expecting one of:
    "TO" ...
    <RANGE_QUOTED> ...
    <RANGE_GOOP> ...
    "] - Query attempted: [(((__smallupdateddate_tdt:[0001-01-01T00:00:00Z TO *] AND __smallupdateddate_tdt:[* TO 9999-12-31T23:59:59Z}) AND __is_running_b:(True)) AND datasourceitems_t:(*{3D6658D8-A0BF-4E75-B3E2-D050FABCF4E1}*))]

This particular error seems to be the reason why my searches for imported brightcove content doesn't return visible results although the related index contains brightcove video document entries.

So, the question is: Does the missing configuration section cause the Solr Error in the Search.log? If yes, how do I add a correct configuration Section that does not produce the Sitecore.Kernel error (the one which states 'Could not find add method') from above.