Plus there's all the promotional stuff as well which must eat into your time as well, of course shows with more of an ensemble cast can spread the load a bit more (well the actors' load anyway) but aside from one Doctor Lite ep a season the incumbent's pretty much got be heavily involved in every episode.
As for the pay, it would be interesting to know how much Capaldi gets paid in comparison with Eccleston, Tennant and Smith. Of the four I would imagine Smith started on the least given he was a relative unknown, and though he wasn't some newcomer you could argue that Tennant was far less known before Who than Chris or Peter.
Then again given Capaldi is such a fan maybe he pays them
I do recall reading something a while back that suggested he was quite well off thanks to some judicious property purchases early in his career so I doubt he's in it for the money anyway.
As for the pay, it would be interesting to know how much Capaldi gets paid in comparison with Eccleston, Tennant and Smith. Of the four I would imagine Smith started on the least given he was a relative unknown, and though he wasn't some newcomer you could argue that Tennant was far less known before Who than Chris or Peter.
Then again given Capaldi is such a fan maybe he pays them

I do recall reading something a while back that suggested he was quite well off thanks to some judicious property purchases early in his career so I doubt he's in it for the money anyway.