If you want your sofa to remain stationary, don't use felt pads or it will scoot across the floor when you sit on it. I use felt pads on dining chairs and occasional tables, and on very heavy pieces (like TV cabinets) that won't move with casual contact. But be aware, you need to keep them clean or they will hold grit and act like sandpaper. Furniture "cups" come in square and round, in many sizes, in brown and tan and clear and wood. I have them under anything with legs or casters. They are also available with "teeth" for use on rugs. I bought most of my furniture protectors at Home Depot.

The biggest problem here is that the bottom of furniture legs are not at an even angle with the floor. Stick on glides either slowly work their way off or wear on one edge until the leg meets the floor. The best working glides have enough swivel/tilt to allow the pad to sit even with the floor. GlideGuys Universal Glides have this swivel/tilt and also roll like a horizontal caster. GlideGuys have interchangeable bases for either hardwood or carpet and felt bases can be purchased separately if they wear or are damaged. GlideGuys are made in USA and can be reused for long life. Remember that the glides used on new furniture are the cheapest option the manufacturer can use to keep the legs from being damaged before the sale and not intended to be a good choice to be used on either hardwood or carpet and should be changed before use.

This may not work for your stools, or the look you have going on, but we struggled with the same problem. I was against this solution at first, but it has worked out well for these stools. They are little rubber feet that slip over the legs. We have felt on everything else. (I think you can see what I mean from this photo . . .)

I have this same tree mat. To be EXTRA careful, I always put a contractor-grade heavy plastic bag under the mat, and then one of those plastic tree bags down under the stand - makes it easier to get the danged thing out of the house with fewer stray needles. A really good stand is essential for not damaging floors. I've used this one now for several years <http://www.hayneedle.com/product/st-nicks-choice-swivel-straight-tree-stand-for-12-ft-trees.cfm?redirect=false&source=pla&kwid=Trees%20newskus&tid=ARET216-1&adtype=pla&kw=&gclid=CjwKEAiA3qXBBRD4_b_V7ZLFsX4SJAB0AtEVuqBT85AylLPtFUSq2cfuyrlRmRHUJV4mVeciSk0fPhoCjZHw_wcB> Yes, it's pricey and there are similar ones for much less, but the "similar ones" really aren't the same sturdiness. If one has ever been awakened by the sound of a tree crashing down in the middle of the night, one will understand my caution! We also always tie the tree to a bookshelf on one side - there is an "eye" screw there all the time, and we use fishing line to secure it. We started his when we had cats, but still do it. The great thing about this stand is that one gets the cup on the tree and then lowers it into the stand and can swivel it until it is "just right" and then lock it in place. It's worth every penny if one happens to have selected the one tree on the lot with a crooked trunk, a "gift" my late husband swore I had!