Well, this is starting to turn out a lot better than I thought it was going to. I finally managed to get an order form that worked. I'm not precisely certain what all the problems were, as I did an awful lot of stuff trying to get it to happen. I did finally manage to assign a package to a group, & I believe that's what actually solved that particular issue.
In retrospect, I'm not sure those plugin widgets actually have to be dragged. I think that once the install link is clicked, the plugin is enabled. Regarding this particular problem, there was an "Add link" by the list of assigned groups, which I finally figured out meant, "Yo, Jackie, you idiot, select the package from the available group, then click the 'Add' link to add it to the assigned group". I think my confusion would've been lessened considerably had the list of available groups populated the assign group dropdown list & then an 'Add to assigned group button been in the tab order. Or a little help blurb that said, "This package has no assigned groups yet. Choose the group you wish to use from the available groups list box, then click the 'Add' link to assign the package. In other words, the label 'Add' by itself wasn't real helpful, as it gave no context. So I'm beginning to think now that just a bit more context regarding some of these labels might be all that's required to make this program quite usable. I'll know more, of course, as I play around w/it further.
At 1 point I found a place where I could choose a layout. I picked layout #1 rather blindly--pardon the pun--& I don't know if that helped the order form initially appear or not, as my first problem was actually finding the link to even add an order form. I wish I knew what the different layouts represented. This has been an adventure, I'll tell yall what! & so the saga continues.