OK. Stumbled across the isssue on a fresh install. Used both 1.03.aa and 1.03.b versions. Issue is - none of the quests is possible to complete. They other does not start at all or loop endlessly at one point (though it seems I can get inn clients to function more or less correctly). Here is the log of the issue:
Judging from the log, quset scripts from vanilla RP is missing, however, installing tweaked vanilla first and then 1.03 didn't solve the issue. Question is - what sort of dumbassery I did, that it is broken? I could try to unpack BSA (never did it before) and check its insides. What I did is to try to recompile the scripts - obviously it failed horribly. P.S. Sorry if my tone sounds rude. Haven't slept in 32 hours and in 4 hours I need to get back to work.