I hate to be that guy, but this is all but guaranteed to have problems with wood movement in the long term. Briefly: boards get wider and narrower as they abso

I hate to be that guy, but this is all but guaranteed to have problems with wood movement in the long term. Briefly: boards get wider and narrower as they absorb and release moisture from the air, respectively. The length remains constant. Anywhere you have a wide board (or glued up panel) affixed cross grain to another piece, you need to account for wood movement. The problematic joint in this case is where the side panels run into the posts that form the corners and support the "roof". Best case is that your grandkids live in an area with extremely constant humidity and nothing bad happens. In any other case, those wide panels are going to get wider and narrower as the seasons change and you'll either split a panel or the Kreg screws will work loose over time. Traditionally, there are a couple of ways of dealing with this. If you're doing mortise and tenon construction, you'd have multiple mortise and tenon joints along the width of the panel/length of the post. Only one is fitted tightly and glued. The remainder are left unglued and loose along the length of the post to allow the panel to grow and shrink in width. Table tops are traditionally joined to table bases using table buttons. Modern figure eight hardware or elongated screw holes are other equally valid options. On the subject of rounding corners, I try to avoid a super aggressive rounding for most furniture. I agree with your dad that this is a great place to put a heavy round over. Those beds are going to be a fort, jungle gym, and probably space ship over time. For anything that isn't going to be used quite so hard (bookshelves, for instance), I usually consider whether the client has kids or not when I'm deciding how much to break the edges. If there aren't kids, I shoot for my old boss's standard of "looks hard, but feels soft", if there are kids, I break them a little more aggressively than that, as much for the preservation of the furniture as the children. Sharp corners wear pretty poorly, and a little extra softening helps keep the finish and wood in better shape over time at the cost of some initial crispness. Anyhow, I hope the grandkids love the beds, and that everything works out without things loosening up over time. Just the same, maybe give them a little shake next time you visit to make sure :-)