1) The AUDIENCE established that. Not Loki.
And again, you guys keep ignoring this point, but Loki WORKED for Thanos back in Avengers 1. The punishment for failure is death. Does Thanos come off as a guy who makes half threats?
2) Back to point 1. Thanos doesn't surround himself with weak losers. Loki knows this.
3) and 4) lol Flee where? Hide where? The ship he is on has been decimated. Thanos and his top goons are right in front of him. Forget Thanos for a moment, do you think Ebony Maw looked like the kind of guy that just lets people slip loose? Thanos crew were able to subdue/take out 2 of Earth's strongest guys on their own (Vision and Strange) And all of them, including Thanos, the guy that orchestrated this cosmic, universe spanning plan were going to get outsmarted by Loki?
5) lol There are levels to this. Did you not see Thanos kill all the Asgardians and beat the shit out of Hulk and Thor? WTF was Loki going to do? He has no super powers standing next to Thanos