Not sure that exact scenario is possible. But there might be a way you could do similar with a bit of guesswork.
You'll be able to set up upper, lower, and side blocks as desired without anyone else seeing them. Content for the middle of page will need adding afterwards to complete the front page.
First step after install would be, TP Admin > Frontpage > What to display on frontpage: Set this to "Go directly to forum index".
Second. TP Admin > Blocks. Turn off all active blocks by clicking the green squares seen on that page. All you and your members will see is the forum.
Then you can add blocks as desired, albeit only top, upper, lower, bottom, and left and right blocks can be used while the "Go directly to forum index" Each block you add has it's own permissions, so you need to uncheck them all so only you as admin can see them.