If one uses the "sgtm" (set global time multiplier) console command and sets the global time multiplier too high, resting objects will start to bounce, bounce around the room, and even stretch. Particularly for the purpose of the rate at which one accrues Sneak XP by movement, what way is there to speed up the game without suffering those physics anomalies?
Alternatively, but a different question, what way is there to increase the Sneak XP that is earned by movement?
I'm going to assume the physics glitch is a symptom of the game engine and the only way to avoid it would be to speed up the game from outside the game engine.
Regarding leveling Sneak quicker... The skills all level up at different rates (http://elderscrolls.wikia.com/wiki/Console_Commands_%28Skyrim%29/Skills)
There may be a user mod that changes the rates or it may be possible to make one... But aside from that, with just console commands you're stuck either grinding it or using 'AdvSkill Sneak ###' to advance sneak via console.
One could try the "Make clutter items static" option in "Better INI Tweaks for Skyrim" (BITS) mod:
[HAVOK]
[...]
; Makes clutter items static so they can not be moved or picked up in-game.
; WARNING: This tweak will make it so your character can not interact with clutter items at all.#bPreventHavokAddClutter=0
;bPreventHavokAddClutter=1
; Install to \Skyrim\Data and the tweaks in this file will override any of the same tweaks from
; the Skyrim.ini file, typically found in C:\Users[USERNAME]\Documents\My Games\Skyrim.
;
; Any line in an INI file that begins with a semicolon [;] or a hashtag [#] is interpreted as a
; comment to be read by humans and is ignored by the game.
I suspect that this option will prevent ragdolls from being ragdolls.
