When I am sitting down, and cast a spell, please make me automatically stand up.

[kaev]

I use either a macro with /sit off or a sit/stand hotkey (from the ability window you toggle on/off with Alt+M) and have never had a spell interrupted after standing (unless a mob smacked me :P). Regardless your "keyboard skills", it's entirely possible that Ctrl+S moves your char a tiny bit and introduces the interrupt chance. Perfect code was never a goal of the EQ developers.