That happens if you go alone with your level 3 char. Take a few high level guards with you (a caran should have those) and defend your stuff.
Funny thing... What if the gaurds betrayed you?

Anyways I love the idea, but its true that the trading part... would be kind of impossible. Pkers will raid these caravans with 20 fold powerbuilds and 5-10 powerbuild gaurds wouldn't stand a chance obviously, dur de durp.
What about outdoorsman alts? 300% outdoor leading caravan across map in 1 minute instead of 40

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You forgot motorized cars man awww...
Needs some reworking but I see SOME potential.