2.6bil is pretty impressive tbh. Just under Luffy's Wano bounty which he got for beating Kaido a "Yonko" but wonder what the "special" bit is about. Could be as simple as it just being "Only Dead/Alive" or sumin or maybe the WG isn't really sure what he's actually worth and just slapped 2.6bil on it. Anyways it's interesting regardless ^^
With regards to Loki/Shanks, could very well be that Shanks walked when Loki challenged him to a fight but then again Shanks doesn't get provoked easily and only really fights when he feels the need to so maybe coz of the collateral damage Elbaf might have taken as a result of it? Regardless, I doubt it'd be anything that would show Shanks in a negative light. Oda loves that dude.