New Room Long wall or short wall?

Short wall. Toe in will be necessary. Experiment with that but I assume it will fall somewhere between firing the tweeters at the outside of your shoulders to having them cross slightly in front of you. I would start with firing the right speaker at right ear and left at left ear and go from there.

By all means experiment to be sure, as it will largely be a matter of preference on most points, but the long wall can offer better sound, particularly in smaller rooms IME. Also in a small room it may depend on how far your rig is projecting an image beyond the outside edges of your speakers - if not much, then the short wall, if a lot, then the long wall may be better for soundstaging. In that regard at least, your system can even be started off along the short wall and progress (by way of upgrades) to the point that the long wall becomes more ideal. Also, often overlooked is the center image. Move your speakers as far apart as possible before the center image begins to collapse. This will allow the center image both the most clarity and the ability to come out more fully into the room. Power conditioning in a system tends to extend this distance, sometimes considerably, so 10-15 feet of separation can be needed, but the maximum distance for your speakers will generally sound the best and offer the most realism as any less distance and the center image will begin to 'fold in' on itself, audibly lessening timbre accuracy and imaging ability within it.

Short wall. My first dedicated room was 10x15 and getting the distance behind the speakers seemed crucial. I did not have to toe my speakers in as radically as suggested above but experimentation with toe in is an easy tweak.
Most definitely treat the room. If you live in the Midwest, I recommend ATS Acoustics for absorption panels. Fairly priced and very quick delivery, even with special orders. No affiliation, just a satisfied customer.
Also, I don't think the Totems will be too much for the room. I was using a pair of Meadowlark Shearwater hot rods in my room and they worked very well.

FWIW, something else occurred to me about the long wall setup (which I've been enjoying many years now). There is known to be an audible comb-filtering effect from the rear wall the closer you sit to it. What I believe is generally not often taken into account here is that this can be mitigated at least somewhat by throwing the right amount and type of acoustic treatment on the rear wall. It's just that you don't often come accross users who've done this, mostly, I suspect, due to the WAF (as in my case). But, just whether or not such a thing could tip the balance for you in favor of the long wall, in practice I can't actually say. But, currently with my own rig with the seat along the rear wall and leaning forward in the chair, the presentation is at it's most 3D-like. When leaning back the presentation becomes noticeably more panoramic. It isn't as though it becomes flat. The difference is more like the difference between sitting in the first few rows vs the middle rows at a classical concert. In either case the system soundstage depth seems to extend well enough beyond the front wall and whichever perspective I prefer is at my choosing. I suppose I should add, however, of course, that true nearfield listening IME tends to minimize many of the soundstaging/reflection disadvantages of small rooms whether along the long or short wall.

Early on in the hobby I read somewhere that having speakers along the long wall is supposed to be the better setup for improved low bass when compared to the short wall setup. Fact or fiction?