I tend to keep the look and feel consistent in the sense that (spurious example) the left of two buttons will always be the affirmative button, or the right, but never a mix.
Beyond that, the UI should focus on allowing the user to complete their workflow as painlessly as possible, where painlessly means accurately and quickly.
That could differ in your case for an end user and an administrator. Here's an example. I encourage people to test their common workflows by literally doing the workflow a thousand times. By common I mean workflows a user may be expected to repeat many times in a given session.
Here's an admin workflow "Click add survey question"->"Select survey question type"->"Enter survey question"->Click save"->"Click 'yes' on confirmation dialog".
Now do that one thousand times and you will find the user has clicked that end yes 998 times and no twice. Lose the confirmation dialog, make sure they admin can undo their changes later.
For the end user, who may only actually use the system once (ever! to complete one survey) having a yes no confirmation at the end would likely help.
Thematically you may want the admin suite to look more muted than the survey page an end user gets simply because the administrator may be looking at it for 3 hours straight. And as hinted at above, the admin user may well be repeating these operations many times, so keep them slick and consistent.
Also, let's not forget that answering the questions in a survey is not the same as creating the questions in the survey. Sounds painfully obvious, but if they survey can take a "other information" type text field for questions, you may not include a spell checker. For your admin pages, entering the text, I'd damn well insist on having a spell checker there. Same operation, entering text, different required result.