aromasin will not hinder gains at all... if used properly, it can help to add to your gains and its also very beneficial in pct as it raises igf levels... just like anything else, as long as its not abused, it can be highly effective...
as far as hcg goes, i would never recommend exceeding 4 weeks of use... i would use hcgenerate before blasting hcg and transitioning to pct...