If I installed the laminate floor over the existing hardwood floor and if I remove the laminate floor 5 years later, what would be the condition of hardwood floor? Would it be usable as long as resanding and refinish?

any concern? any advice on installing the laminate floor over the hardwood floor so that hardwood floor would not be too damaged?

thank you for your advice

As long as it is not all over a concrete substrate, you'll be fine.