In the step 2. you write that you "Ask everyone to accept proposal i", but to satisfy the safety property of Paxos you can only accept proposals from round "i" if you were a participant of the round "i" in the step 1.
Ah true, I should have probably written "all round 1 participants". It can be enforced by the receiver as well. There are some other implied receiver-side steps that I did not write down, such as rejecting all proposals with a sequence number <i.