HOBrO2 Lewis Structure, chemistry homework help



I have a few questions regarding drawing the Lewis structure of HOBrO2.

I have attached the lewis structure given in my answers below.

My issues are:

1) How did they determine that the one drawn is the most stable? The answer says other options such as HOOOBr, HOOBrO and HBrO3 may also be drawn but the one drawn is more stable. On the internet I could only find websites about the stability of cis and trans isomers, but not about the stability of different structural isomers.

2) Why does bromine in the picture below have 12 valence electrons (2 attached to Br only (2) + 2 double bonds (8) + 1 single bond (2)  ; 2+8+2=12 )? I thought we aimed to have 8 electrons in the outer shell when drawing lewis structures?