How much research experience to include on a CV?
What you will soon realise is that there is no one CV to rule them all. More precisely, you will find that you need to tailor your CV for each job application etc, by (de)emphasising various parts of it. Getting a summer internship at McDonalds? Emphasise the hamburger flipping. Applying for a grant, emphasise the research. 

Thus how much research experience you include in your CV depends what you are planning to use your CV for. If it were to get a PhD position, I would say "Yes".

Publications stay. They always count.

Gradually, the research projects you did as an undergraduate will become uninteresting for your CV, for example, as you start filling your CV with new and exciting activities.  This always happens. When you are starting your research career, you will be asked to review papers. You can list what journal/conference you reviewed for on your CV. Later you will be on conference PCs or journal editorial boards. Then all of the reviewing experience will become irrelevant for your CV.