1) fast travel - double clicking on a room exit and get instantly teleported.
I don't like the teleportation, I prefer to have a "run" animation and execute actor.run(x,y); whe the player makes a double click
2) hint system - shows all interactive objects in the room that will be important, like exits or items etc.
Only for newbies, If you has two game modes (normal or newbie), is good, if not, no.
3) action menu/action coin - already standart in wintermute. But still very interesting, i think this gameplay element was invented by LucasArts in CMI and is the final result of reducing its verbal system to its basis. Sierra and other companies already where using a similar system but it was a very annoying "click right for the next verb", where you had to scroll through all minus one button if you are unlucky. LucasArts fixed this issue with its action coin and im a little bit disappointed that this feature is still missing in most commercial games.
The Lucas system is very simple and fast, the "hand icon" is valid for get, use, and makes special actions, in some cases the "talk icon" can be used to talk and eat. With the two systems is possible to do the same actions, but the Lucas system requires more imagination for the player. The sierra system required more work for the programmer. I prefer the Lucas system, I don't work much more with the menu system and requires more inteligence / imagination for the player.
Then i was thinking about gameplay elements that are still a typical problem with adventure games. One thing is the annoying standart sentence "i cant do this!"
Games like A Vampyre Story try to solve this with funny dialogs. So instead of getting "i cant do this!" or "that does not make sense!" you get the sentence "Oh hello little door. How are you doing?".
That is ok for a game that uses humor but it has some disadvantages:
Yes, the "I can`t do this" is horrible, I prefer the second option. Obiously, this option result in more job for the programmer. I've in disapoinment with you idea, I think that this system can be used in any kind of game, humoristic or serious, if the game is serious you can design every object for provides help to the player and you can limit the actions (not is locig that the player talk with a door, then you don't must permit that the player talk with the door). Of course, this is more work for the programmer and the designer.
