Just confused

Try and plug EVERY equipment that you have into the SAME power outlet. This will minimize ground loops (which cause humming, buzzing sounds) which will sometimes be EXTREMELY annoying & difficult to get rid of. Keep the power cables as short as possible to help this.  The idea is that ALL the earth connections on ALL your devices be at EXACTLY the same potential.  Even a skew of half a  milivolt will cause humming and buzzing sounds.

Ground loops are not usually a big problem unless you have turntables & associated phono preamplifiers (or any device with very low input signal levels), but it is always good practice.

If the total current requirement of all your devices exceed the capacity of your outlet (which is extremely unlikely unless you have 1000+ watt amplifiers), you can upgrade it to a 20 amp circuit later.

I would add a nice rug and just enjoy the music. As you get much more accustomed to the sound and your hearing becomes more astute, you will then to be able to find flaws or not in your system. I wouldn’t blindly throw money at cones, spikes, better cabling and cleaner AC, etc. until you have lived with the system for a while. I would say a good six months unless something really stands out as very annoying. A rug will definitely help, otherwise the room could be too lively and bright.

Most of us here have our own ideas so you will get probably 20-30 different answers or more. The main thing is to have fun and enjoy the music

Try a large enough rug to place under the speakers and far enough in front of them to address first reflections from the floor.

If a smaller rug is the only option...place this in front of the speakers to address first reflections from the floor. Buy some brass footers for your speaker spikes. These are little saucers with an indentation in the center to cradle the spike. I cut out some leather circles to place under the brass footers to prevent the odd buzz from an uneven wood floor.

The most important thing is just to try stuff on your own. Read a couple of good books on acoustics/speakers etc.. This helped me quite a bit.

I’ve just been thru this. Concrete slab floor is great for vibration control. Rubber feet sounded much better than spikes. Might be because it’s hard to get 4 spikes perfectly balanced on concrete with zero movement. They always rock a bit. So, I put the factory feet in instead of the spikes. Yes.  I tried various isolation feet. No. I even tried springs because some people here think that they are the ultimate isolation medium- capable of isolation below 5 hz I was told.  No.  Loss of bass definition.  For acoustic control purposes I decided to put down carpet and pad along with other room treatments. Yes. Huge improvement.  But, I felt the bass definition could improve. Back to spikes thru the carpet and pad. Yes! I’m very happy.  And they don’t rock at all. I can’t explain that part. Carpet shouldn’t make a difference when I know the spikes go all the way thru. That has been my experience in my room. I’m not saying I think my way is what you should do. I think every room and system is unique. I had fun trying things and seeing what worked. I hope you do too. If I spend too much more time isolated in my house I might go crazy and try bolting the speakers to the floor.  🙃

I wouldn’t spike anything to concrete/tile. I use Herbie’s Audio Lab sliders under my speakers on ceramic tile they work great and you can tweak your speaker position much more easily.