I have used an Orca in a wormhole for a nomadic life style with reasonable success when wormholes were first introduced, however this was when wormholes were relativly quiet and there were no POS's set-up. Basically my alt in the Orca with cloak was the prober / hauler and remote repairer and main character had choice of Drake, Covetor and gas harvester in ship bay which he swapped out with his fully pimped prober.
Now that most class 3 wormholes are occupied and wormhole space is a lot busier I have found it is dangerous to try and maintain this life style except possibly gas harvesting in class 5 / 6 wich still can generate some good isk. This normally means looking at a second tier in wormhole which is often quieter but does pose questions of getting the orca out at a later date.
If you get a quiet wormhole with some good grav / gas sites you soon run into the problem of filling the orca and then you have to get it all out to a high sector exit as I would not try to run the Orca through low or null.
Not worth the isk / effort in my honest opinion these days, go with a POS or look to join a wormhole corp.