Just confused about where to start

Hello all,

I'm looking to add speakers to my audiophile setup which currently consists of (very high end) headphones. I want speakers for everything the headphones cannot do - simple enough. Problem is, I'm having difficulty deciding which gear I want to buy. I demoed a pair of B&W 705 S2's today and was very impressed. Unfortunately, my budget isn't that high. It's $1500 total, for the speakers and amp combined. Source is a computer. I listened to a cheaper pair of B&W bookshelf speakers (can't remember which, but were around $1200) and was not impressed. I am leaning toward bookshelf speakers but don't know if getting floorstanding at this price point would be a large increase in quality. The room they will be placed in is only 100 square feet. I am willing to buy used.

So, my questions, summed up are:

Is bookshelf a better option than floorstanding?

Is it worth looking at cheaper B&W models, or should I look at other companies altogether?

At least with headphones, I like a pretty neutral sound, if not a tad warm. Are there any companies that predominantly have this sound signature?

How should the room size inform my choice of speakers?