wrote:
if there is none, please suggest the approaches/theories/
speculations (in string theory, CQG, or even alternative theories) you
believe are actually the most interesting/promising in potentially
describing physics where space and time no longer is a foundation but
only a low energy emerging property.

There is a number of penetrating papers by J. Barbour
http://arxiv.org/abs/gr-qc/0309089
http://arxiv.org/abs/gr-qc/0012089 (and other related papers
cited in the first reference above),
as well as his book "The End of Times", (Oxford Univ Press, 2000).

See also http://arxiv.org/abs/gr-qc/0610061 (pages 107-163),
and a recent work http://arxiv.org/abs/0712.3660
for my approach.