Mehment,
These situations are NOT gold plating. According to Wikipedia "gold plating" is the following:
Gold plating in software engineering or Project Management (or time management in general) refers to continuing to work on a project or task well past the point where the extra effort is worth the value it adds (if any). After having met the requirements, the developer works on further enhancing the product, thinking the customer would be delighted to see additional or more polished features, rather than what was asked for or expected. The customer might be disappointed in the results, and the extra effort by the developer might be futile.
Gold plating is also considered as a bad project management practice for different project management best practices and methodologies such as: Project Management Body of Knowledge (PMBoK) and Prince 2. In this case, gold plating refers to the addition of any feature not considered in the original scope plan (PMBoK) or business case (Prince2) at any point of the project since it introduces a new source of risks to the original planning i.e. additional testing, documentation, costs, timelines, etc. However, gold plating does not prevent new features from being added to the project, they can be added at any time as long as they follow the official change procedure and the impact of the change in all the areas of the project is taken into consideration.
In both questions that you list, the team has found ways to improve the product/project. And the question is "What should you do if you find ways to improve the product/project?".
The correct answer is: Discuss your ideas with the customer and let the customer decide.
If you go ahead and implement your ideas WITHOUT asking the customer and without going through change control, then you have scope creep and possibly gold plating. But if you run your ideas through the proper channels and processes, then you are following project management best practices.
