I apologise for what may be to some seem a straightforward question; I am an enthusiastic amateur!

I am developing an application that when being configured on "day 0" offers a use the choice of rating the item in 2 or 3 dimensions (in a select field called dimension).  

Thereafter when the enduser creates an article on day 1+, if they have configured the application as 2 dimensions then only two rating fields will be offered (e.g. rating for probability and isotope) in the content form.  If it has been configured as 3 dimensions (probability, isotope and scent) then three rating fields are offered in the content form.  Each selection in the three fields is scored and multiplied out.  I was planning to use a conditional state on the scent field that if Dimension is set to 2 it is not visible (and has a default value of 0).

Thus far, I have created two categories called 2-dimension or 3-dimension with a parent category of "cat_dimension" and stored the value of the field Dimension (being the dynamic select value) in a separate table. This all works fine. Each article will have have a hidden field called dimensions that shows (another) category id = to the value contained in the field Dimension.  Is this the best way to achieve the result.  Each article already has a default category of "score".

My issue then becomes more computational in nature.  Is there a "relatively" simple way to attach a numeric value to the score arising from each dimension (each dimension is a dynamic select field); e.g. the scent scores would be strong, fragrant, light, weak (e.g. a scent score of strong=4, fragrant=3, etc).  I know that this can be done with select simple fields but I need to use dynamic select to allow the client the ability to define their own scoring system.  I then need to create a field which multiplies out the three scores to generate a result.  

Thank you in advance for any help you can provide.