I understand the idea of bodies not rotting away due to some devine influence, but it seems a bit disrespectful to have a body on display. The soul is no longer there, it is just a container. I have also noticed people kissing the box, is this some sort of worship?
At the root of your argument lies a contradiction. If a body is a mere container, then how is it possible to disrespect it? If it’s just a pile of decaying stuff, then what does it matter what we do with it?
Resist the urge to flirt with gnosticism. Our bodies are temples of the Holy Spirit, and will be glorified at the End. They must be treated with respect after death, and there is nothing disrespectful about displaying the relics of a saint, or venerating the same. Veneration is not worship. Veneration of relics goes back to Biblical times (St. Paul’s handkerchiefs) and even back to the Old Testament (Elisha’s bones, as an earlier poster pointed out).
As for kissing the box, there’s nothing idolatrous about that. I kiss my medal of St. Thomas More all the time. Why? Because I can’t kiss him. If he was physically present, I’d run up and kiss him, not the medal. For now, though, the medal is the next best thing. I also kiss the crucifix on my rosary, as a way of expressing love for Him who hung on the Cross. And I kiss my Dominican cross, in part as a way of thanking God for my Domincan vocation, and in part because it gives me comfort.
People who pass judgment on these Catholic practices are really only depriving themselves of a great many consolations they could otherwise have, and indeed were meant to have. As with a nearsighted person who doesn’t wear glasses, life is a lot harder for them than it needs to be, but they don’t realize it because they’re so used to it.