Cleaning out the Away Camp will make the Templars hostile, and pretty much end any chance of becoming a Templar yourself.
Given the numbers of Rapax in the castle, you may want to wait on doing the Away Camp until after you've become a Templar and gotten everything you want from Ferro.
Becoming a Templar does, of course, bring an experience award (so does killing Al-Sedexus
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Nightowl2