Perhaps a small bit of help in these two areas.

[johnemccauley]

When I am question. i usually que for a dungeon.. If I accept the guide for the dungeon. Once completed, it does not go back to where I was questing. I have to manually search for where I left off. Also.. thanks to most titles and achievements being account bound now. I find it difficult to know which achievements and were done by my main and which ones were done by my alts. Perhaps you can help to separate this where blizzard fails to do so.

[cabby]

For the guide switching, if you open the guide selection window after running a dungeon guide you should see the name of the last leveling guide you used under the Leveling section name. If you click on that guide name it will load up the last guide you were on and the step you were on.

For the achievement one, there's nothing we can do for that. Blizzard only tells us if you did the achievement or not, not which character did it so since they're account bound it will just show up as being done.