I am a noob in every sense of the word. Here is my question - are there practical limits (other than transfer sizes) to the number of controls? For instance, if I have a page and that page contains windows, dialogs, tab pages, panels within those tab pages, grids - what governs any limits? Is it purely client side memory or are there some page limits as well?
"Screen real-estate" is one of them. A video screen is somewhat larger than a sheet of notebook paper. A "capacious" screen is probably about the size of two pages side-by-side. That's it. And visual controls (such that can be used by folks like me ... age happens ...) are relatively large.
Another consideration is the visual complexity ... of just how many "things" a user can visually comprehend at any one time. I believe that the number is something like, "eleven... and that's really pushing it." So, you quickly find yourself changing your design so that it is "comprehensible 'at a glance,' without instructions."
Basically, then, if you find yourself asking "what are the limits?" ... i.e. of the technology ... you've probably long-ago surpassed the limits ... of the user.