All the scripts from 07 work in Stable; most the scripts from 05, 06, work in Stable as well.
As for cut scenes when you first create a character, that’s easy (in sadscript).
Make the cut scene in flash, and put the swf file in the Client\Flashs\ folder.
Then, in the OnNewChar sub (I think it’s in the Scripts\Events\ folder, in the OnNewChar.ess or something) add this command:
Call Flash(Index, “Flash.swf”) where Flash.swf is the name of the flash file.
Then, when someone creates their new character, the flash file works.
To answer your other question in your opening post, too, my game, Retarded Online, has no source edits.
It has a fully scripted spell system (where the player’s spells can level up), a scripted arcade, and many other various features; virtually anything is possible via sadscript in Eclipse; I even wrote an experimental turn-based battle system in pure sadscript, someone else attempted a pet system via sadscript.