CRM4: inserting data field from custom field in related entity depending on the contact language

We faced a situation where we had some data fields in a phone call template, but we wanted to use custom field for this data field depending on the language of the contact, also we had some picklist that is always coming in the user context language, and we wanted it to depend on the contact language
To solve this, I have updated the template with some text pattern for each field, for the picklist and the custom fields, then I have created a plugin for the phone call, with the below steps
1- Get the contact language
2- Get the custom field depending on the language
3- Get the localized picklist label for the language
4- Search the phone call description for patterns, and replace with the localized value
5- Update the phone call with the new description
To get the localized lookup label I used the metadata service to get all pick list values, then compared each picklist option with the value and the language

                        Option[] deptOptions = RetrieveEntityPicklistValues(metaService, EntityName.incident.ToString(), _attCaseInternalStatus);
                        foreach (Option option in deptOptions)
                        {
                            if (option.Value.Value == (int)internalStatus)
                            {
                                foreach (LocLabel label in option.Label.LocLabels)
                                {
                                    if (label.LanguageCode.Value == languageCode)
                                    {
                                        newCaseInternalStatus = label.Label;
                                        break;
                                    }
                                }
                                break;

                            }
                        }

        public Option[] RetrieveEntityPicklistValues(IMetadataService metaService, string strEntityType, string pickListName)
        {
            try
            {
                RetrieveAttributeRequest request = new RetrieveAttributeRequest();
                request.EntityLogicalName = strEntityType;
                request.RetrieveAsIfPublished = true;
                request.LogicalName = pickListName;

                RetrieveAttributeResponse response = (RetrieveAttributeResponse)metaService.Execute(request);
                AttributeMetadata retreivedAttributeMetadata = response.AttributeMetadata;
                if (retreivedAttributeMetadata is PicklistAttributeMetadata)
                {
                    return ((PicklistAttributeMetadata)retreivedAttributeMetadata).Options;
                }
            }
            catch (Exception eGlobalException)
            {
                throw;
            }
            return null;
        }

Same concept can be applied with any template, a more generic solution could be developed by creating a plugin on template retrieval that replaces the values for any retrieved template

MS CRM Plugin development best practices

While i was debugging, I noticed that update plugin was lots of times, and each time it was called all case properties was sent in the context, While not all of them are updated. so i started searching on how to make sure that only the updated property is sent to the update plugin.
I found this article which is very useful
http://blogs.inetium.com/blogs/azimmer/archive/2010/01/25/plugin-best-practices-in-crm-4-0.aspx

In summary what i was doing wrong is like the following:
- I was doing retrieve entity then after, i was doing update to that entity, while the correct thing is that to do update without doing retrieve.
- When retrieving for any other reason, i was getting all columns, the correct thing to do is to get the desired columns only