The thing with Arabella is, there are multiple story trees whether she dies or not. If you're not a fan of digital children dying, then sure, reload, but if you're not fussed either way, the richness of gameplay remains both in the event of death and life (you just get the dancing lights amulet sooner if she lives).

What I don't like is when failing a die roll totally closes off one avenue of play (eg Lae'zel coming to kill you in the night), If something important can be decided on a die roll, there should always be a harder route to the same outcome. Good example: if everyone fails their perception check on the lever in Selune's Temple that opens the way to the Underdark, you can still solve the puzzle and get through. Annoying, but at least that option isn't completely gone. So even if you've sworn, for whatever reason, never to reload, you can still gain the experience and find the route ahead.