For the first part about taking but not editing, this is likely best served through a security role setting where the user can 'add' but cannot modify. The intent here is that they have to take the quiz in one go - save, and then they're done.
For the formula score - is the intent to give them a point for completing the question or are you assigning scores based on correct answers.
If you care only about them completing it - then your score would look something like:
If( [Question 1 Answer] != "", 1,0) +
If( [Question 2 Answer] != "", 1,0) +
If( [Question 3 Answer] != "", 1,0) +
If( [Question 4 Answer] != "", 1,0) +
....
And so on. You're giving 1 point each type they provide an input for each answer.
If you're trying to compare to the correct answer, it will look more like:
If( [Question 1 Answer] = "Answer to Question", 1,0) +
If( [Question 2 Answer] = "Answer to Question", 1,0) +
If( [Question 3 Answer] = "Answer to Question", 1,0) +
If( [Question 4 Answer] = "Answer to Question", 1,0) +
...
And so on.
The only thing to consider with this is that if they can see the score as they're entering - they can easily just go change their answers and check to see the score change to make sure they pick it correctly . You can set up the form to only show the score on 'View' to handle this - so that they only see it after they save.
------------------------------
Chayce Duncan
------------------------------