Either your friend is none too bright when it comes to speaker placement or he is pulling your leg. Take your pick. Good advice above - I don't need to repeat.
However, your comment about having lots of cushy furniture is something I can identify with. I have a room a little bigger than yours and I have lots of furniture in the room including book cases, CD cases, chair, couch, desk, and other stuff but no room treatment. The room is somewhat live and it sounds really good. Punchy and dynamic with excellent imaging.
I realize that this doesn't exactly relate to your question but one of the best tools/skills you can use is the slap echo test. Clap your hands and listen for the echo and decay. Do this around your room and then try it in different rooms in your house. As you gain experience you can use this test to get a good feel for how a room sounds. If the sound you hear is a clearly defined echo with a fairly long decay then that indicates you will have a problem. If the sound is dead without hardly any decay, your system will sound lifeless. You want to hear a smooth decay without a clear slap echo. Once you get proficient with this go over to your buddy's house, clap your hands while moving about the room, and then tell him to move his listening chair 2" one direction, his rug 6" in another direction, and change the toe in by 8 degrees. 😁
My point here is that if you start moving stuff around or adding or deleting furniture there is a simple way to get a sense of what is going on with the room. It won't tell you where the bass nodes are but it's a good tool for managing absorption and diffusion. When you hear a different system it can also provide good information about why it sounds the way it does.