telling you, its the damn z-fighting values. :) at least for me it was. and it kinda all makes sense to me: what those z-fighting tweaks do (as far as i understand) is to load LODs of far away regions. so when you leave Falkreath, Skyrim tries to load all the exterior landscape, objects, LODs and so on. So i guess this is where SSD or Video Memory or something comes in. If you have a fast enough system, than it seems to work. But if you have a mid-range rig, like i do, without SSD and only 1 gb of video memory, plus massiev amount of mods, than skyrim seems to get problems with the amount of memory needed to load in all those landscapes.
Thus deinstalling Distand LOD Mods, Map Tweaks, and Z-Fighting Ini tweaking is likely the reason for infinite loading screens. therefor i would recommend that STEP includes a warning in the section with the z-fighting guide. cause for me it was definite those ini values.