Robshaw is still my favourite for the 6 shirt. His work rate frees up Morgan/Kvesic to do their thing, and I think he's a great jack-of-all-trades to have.
It depends. If Kvesic blows everyone away at the start of the season and claws into the XV for the AIs, then it may be that Lancaster moves the captaincy to Parling or Morgan or someone.
But if it takes longer, then there may be enough time for one of Robshaw-Croft-Wood to shine through, or it may be even that another captaincy contender breaks through to England.
For captaincy, I'm gonna risk inciting the fury of a thousand forwards, but I'd be tempted to consider Burns. I know the taboo of giving backs/fly-halves the (c). But he's confident, chatty, likeable, is a student of the game (spends time analysing games with Twelvetrees) and can make quick decisions.