John in NM
I'm going to disagree with four of your thoughts in particular, however, my intent is to provide another outlook more that to say "wrong, wrong, wrong!" I think everyone's outlook tends to be limited by their own experiences if they allow it to be - many people do because that is far more comfortable than to be drowned by the many options available to them. So don't take my disagreement to be saying "wrong".
First off, many people move. Many people move many times. Many people consider furniture they've built or their family have built to be valuable and want to keep it for generations. I design for the convenience of moving stuff, I've done a lot of moving.
2 and 3 I agree with whole heartedly.
4 & 5 are only true if you design them to be true - such as was done with the metal frames the store sells you at exorbitant cost like the box spring. One need not design things in such a way as to require a foot board, but a foot board can in fact be structurally necessary. One big advantage to the traditional head/foot boards and posts all held with M-T's and bolts is that its very easy to move since it can be disassembled. As I said, many people move.
6 - yeah, whatever. I hate under bed storage personally. I prefer a vast, open expanse under there so that the cat can't hide effectively when we are packing to move.
To each their own. Your preferences formed by your own experiences have probably served you quite well, as have my very different ones. That's the great thing about these kinds of forums, people get to sample the preferences of others without having to go through the experiences that formed those preferences.