Looking for suggestions on what rug size/placement for a room that will have a bed and and small desk area. Plus any other design tips for creating a combined space. The background is that I plan to add a (small) home office space to a room that is a guest bedroom (with existing full-sized bed), and the room needs a new rug and other updates. To keep the "home office" element small, I'm planning to get a minimalist desk (e.g. like this), so it can easily revert to a nice guest bedroom down the road.

I am trying to figure out what size rug to get. My design inspiration is the hotel room shown below-- the placement of door and windows is similar to mine (I will not have the second bed, and there is a row of closets in the wall furthest from door.) My room is 10x15. (so narrower between bed and windows). The room shown has a rug over most of the floor.

I was planning to do the same (leaving some space around the edges--maybe a 9x12 rug). But then I kept seeing design tips about centering area rugs around the bed only, with the rest of the floor exposed. I think the room would benefit from a large rug to cover the (somewhat worn) parquet floors and to give cushioning (the room is on a cement slab), leaving a little space around the edges. I don't want to create a separate office "zone" with 2 rugs, either. (I want the desk area to be subtle). So my questions: Are there any rules of thumb for placing a rug in a multi-purpose space? Are there drawbacks of covering the whole room with a rug?

Will it be awkward to have the floor exposed around the rug if the desk and bed are both against the walls? I think that at the minimum, I would need to make sure that the place for the desk chair is not half-on, half-off the rug...

Advice welcome!!