Hi Christina

Why not let the data "do it for you" ex post? Try using exploratory factor analysis or principal components analysis over the 65 questions and N responses and see what PCA pulls out as linearly uncorrelated variables of a manageably smaller lower dimensional set. You might find that your original 4 dimensions change (increase, decrease, or change their constituent questions)?

Alternatively, use an expert panel to put ex ante weights on the categories of questions (i.e. over your 4 pre-specified dimensions). That's tricky, because it assumes you got the information structure right both as to type of categories, weights of categories, constituent questions within each category and finally equal weighting of questions within each category. That's an awful lot of structure to assume!

Best

Marco

Together with factor/PCA analysis you can use reliability tests/Cronbach alpha to test scale reliability. Read more in http://www.amazon.com/Multivariate-Data-Analysis-7th-Edition/dp/0138132631 and https://www.researchgate.net/profile/Vesna_Spasojevic-Brkic/publications/?pubType=article&ev=prf_pubs_art

Check the validity of questionnaire, and reliability doing exploratory analysis PCA/factor analysis. This will converge your dimensions to pertinent ones. You can do it manually, or better use a statistical software, which give speedier outputs, and more importantly graphical ones.

This analysis must be complimented using some quality tools. The nputs (as data, or weights) may be generated again by quality techniques.

It is always wiser to use more than one, or better modes like Triangulation to solicit sufficiency in analysis/ study

Value-based analysis is one way to provide weightage to one or more of your  categories? 

In this regard, the following paper may provide some insights as to how to  proceed in your case. 

Take a look...

Article Towards Balancing Multiple Competitiveness Measures for impr...

You can use AHP technique to provide weightage to the 4 different dimensions. You can read many articles related to SWOT-AHP or youtube videos on AHP.

I think it will help your work. 

Data envelopment analysis (DEA)

Benefit of the doubt approach (BOD)

Unobserved components model (UCM)

Budget allocation process (BAP)

Public opinion

Analytic hierarchy process (AHP)

Conjoint analysis (CA) are some of weighing methods can be applied as suitability.

Data envelopment analysis (DEA)

Benefit of the doubt approach (BOD)

Unobserved components model (UCM)

Budget allocation process (BAP)

Public opinion

Analytic hierarchy process (AHP)

Conjoint analysis (CA) are some of weighing methods can be applied as per suitability of the research.