As a sitter for players, I often find myself at a road-block when trying to make the player's village better. I think all of us, at one point or another, filled our entire village with crannies to avoid raids. One of the players I am currently sitting has 5 level 10 crannies, and will be gone for a week! As a sitter, I can't demolish the crannies. I can't get him silver either. I can't make links for him. I think there should be an option, if you REALLY trust your sitter, to have full account access. It would make the game a lot easier for everybody who sits for other players.
Might be why the vacation option was introduced, if the owner is away for a period, then they should have selected that option.I often sit for others too, but if they're away I request a list of instructions to complete and limit myself to that as well as random monitoring of any potential incomings, The ability to operate Sitters accounts as your own is similar to Multi-accounting.
Please don't. Sitters function is already abused by multi-accounts.
While I can appreciate your desire to help improve other's accounts, each account must be autonomous in its own right (i.e. it's own unique owner(s) and agenda for the server). My understanding of the sitter function is that it's designed to plug online access and help keep things ticking over.
One option might be to chat to the player and offer your perspective on the game, and the benefits of replacing the crannies. Maybe they haven't found a building they need/want and so build crannies to fill the empty space? If you get on well with the player, you could also consider dualing in the future too. I've found that sometimes players are open to and appreciative of a bit of guidance, they just don't always ask for it. There is also the point ELE makes in that it could be abused as well.
That said, I understand the frustration when you're sitting for someone and you're desperate to see a trade office go up and there's no room! :p
And sometimes you just have no choice but to build lots of crannies.. Having spawned next to the most insane raider ever on US7r1 I had no choice but to cranny up and hide until I could get settlers out. He raided me constantly.. Was afraid I'd make TTs and come after him. Eventually we became friends and I had a great time playing alongside him. But the 4 Gaul crannies were my absolute savior.
But on to the serious issue. What are the boundaries between a sitter and a player? Should a sitter really be able to launch an attack vs. a raid? Should a sitter be able to send chiefs? A demolish can be tricky. A sitter who demolishes a residence could allow a chiefing to take place. (Intentional or not, someone could do it just to make a space to build another granary with disastrous results. ) I understand the issue you're running with, but there are always lots of plusses and minuses with these things. Balance is the way of the Travian Developer.