it lowers the aromatization of androgens into estrogen.
How does dht impact estrogen? Like winny or any other dht like compound.
Yes, and winstrol does not aromatize.
Second question I can't really answer but bloat or gyno from winstrol, masteron and such is very uncommon (impossible?).
However since you are using sustanon you might need arimidex but probably not at 1mg a day since you are only using a small dose of sustanon.
Start low and if you feel that you get to bloated increase the dose. You do not want too low estrogen.
And as mentioned before both winstrol and arimidex can be is harsh on the joints.
Definately skip the nolvadex.