Well, I don't like the idea of "higher" and "lower" - but that debate has already been hashed out (I think in the "Female Sub-Deaconate" thread). As far as not blessing "up" - it depends; during liturgy, if the Bishop is in the pews and the priest is in the Altar, then the priest should bless when appropriate, especially if the priest doesn't know a bishop is there (I know, unlikely, but it has at least happened here, where some of the bishops show up incognito). THere is no blessing for the Deacon, so it would be impossible for him to bless "up" the ladder. But, like, if the priest were visiting the Bishop in the hospital, or something like that, then it would be appropriate. Otherwise, the Bishop should be blessing, if only for the fact that he represents Christ, and the especially the entirety of the Church community.