Furniture leg pads, rubber or felt, which one is better to buy?

Rubber is resistant to abrasion and is not suitable for high-grade solid wood flooring for furniture that moves frequently; 

felt is not abrasion-resistant but can protect wood flooring from scratches caused by movement. 

It is used for high-end solid wood flooring and furniture that does not move often. !

Protective film or pad on the floor

Protective film or pad is definitely not appropriate. Today's floors are painted and the surface is bedding, which can easily cause staining. The floor was completely scrapped. Now that you think about renting out money, don't bother the floor. If you can find a careful tenant, it is certainly better. If not, write "No damage to the building structure" on the agreement, and that's it. Big deal, change the floor in the future.