Regarding Sally's musing on Robert Holmes...
I think it is harsh to judge him on how he wrote for the various characters as he wrote so few episodes for this series (two in Series Two, two in Series Four). It's inevitable that in a series like Blake's 7 there are going to be episodes in which one or two characters are concentrated on, with the others sidelined, just as there are episodes which are ensemble pieces. The responsibility for making sure that each character gets his/her fair share of the action must surely rest with the script editor (and RH was only a writer on B7). Actually in his Series Four episodes, he does quite a good job on sharing out the action; in Traitor, Tarrant/Dayna are in the spotlight, while in Orbit it is Avon/Vila. Only Soolin gets neglected, presumably because she was something of an afterthought (didn't they originally want to retain Cally, but Jan C didn't want to continue?) and there wasn't much for RH to go on with her.
Best wishes, James