Hi Lobbie, see below for some comments around these.
Think these are fine as a guide, but suggest a little trial an error here - you also want the clusters to fit the purpose, not just the best from a statistical sense. So you can also play around with which variables to use, and profiling to get a sense of the solution (can use the segment profile node here). This gives some more detail around approaches to selecting the no. of clusters: https://v8doc.sas.com/sashtml/stat/chap8/sect10.htm
Yes, it measures the separation of the clusters, so higher is better
It's the higher the better for both. RSQ this is the proportion of variance accounted for in the data, and RSQ_Ratio is similar but takes into account within vs between cluster variance. These will keep increasing to a maximum where the number of clusters = the numbers of cases, so you're not looking for the higheset but actually an inflection point where the rate of increase is small
Also try looking at the CCC plot and see if there's some levelling here.
Cheers,
Troy
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