i find the inconsistency between the two games a bit unnerving to say the least. admittingly, i really like the new psychic strength system but did they really have to completely change the casting mechanics? two of my gaming group are warhammer fantasy veterans and strong advocates of wfrp (2nd edition) system which is similar to the DH one. and since i rolled the astropath in our new RT campaign the issue came up. so, can it be done? can astropaths be modified in such a way that they can peacefully coexist with sanctioned psykers without causing problems with game running? or should such a task be condemned as heretical and abandoned?

only solution that i currently see is manually calculating power tresholds for the RT exclusive pychic techniques so that they correspond to DH mechanics. but then again, this is my first experience with playing psykers (and mages if we take into cosideration my wfrp experience). any helpful info?

A lot of astropath powers have equivalents in DH, so you can use them instead. For the other powers you will need to decide on their threshold and overbleed.

Then you have the issue of how each class acquires powers.

The easiest solution is to have sanctioned psykers from Dark Heresy using that system, astropaths using the Rogue Trader system. You could have them each using seperate phenomena/perils tables, but it would be easier to just pick one of the tables and use that.