We put up the bookshelf/cabinet and then loaded the ancient stereo, most of the games, and the important books onto it. We did not put the cardboard backing on it so that you can reach the electrical outlet for the stereo. However, this may have been a mistake, as the shelf is lacking some cross-bracing stability without it. We didn't throw out the cardboard in case we change our minds later.
After establishing the bookshelf in the corner, we put the collapsible table up, making sure that all doors open correctly. We took the time to add a few more screws to the center line of the drop table support along the stud, since the rest of the mounting is just basically hanging off of the paneling. We also cut into the vertical seam covers to ensure that the table was flush to the wall. The center of the table, including the little right-angle brace, now has four screws sunk into the stud behind it.
With Mom's permission, the living room furniture is now rearranged to allow for better front-door passage as well as reinstatement of the shorter (stained and backless) bookshelf. I'm considering replacing said bookshelf with two narrower and 2/3 height shelves for either side of the loveseat. Maybe they'll match the new bookshelf in the opposite corner. I shall ponder and consult at a later date on that thought.
Unfortunately, the storage shelves over the bed in the screened in porch were canceled for lack of tall. Neither C nor I could figure out a safe and sane way to mount the shelving to the dropped section of the ceiling. The insane way would have required either bringing up a complete ladder and moving the bed, or putting a step stool on the bed itself. Neither option held much appeal. And rather than leave it until next year and have half of one year's edition and half of another, I returned everything to Home Depot this morning. I figure that I will try again next year when I have Achaosofkittens or other tall assistance.
With a shout-out to Blushing_Grace for all of the IKEA assistance!... I present The new shelf, sitting where a short black antique cabinet used to be.
The drop table, sitting where the old demoted kitchen table used to block the swing of the front door as it opened.
All doors open, proving that we measured and mounted everything correctly!
The other end of the room, with the futon and loveseat swapped, and the bookshelf now against the wall rather than perpendicular to the front door.