I also wonder if there are some specific rules for variable ommition. I found one example, where they excluded those having small MEAN discriminance value (DV) across first two dimensions. But these first two dimensions explained only around 30% of total variance.
And this is happening with my data as well. Some variables do not discriminate at first two but for example at 3. or at 5. dimension. Should I ommit them and only look at first two dimensions?
Till now I tried different options to eliminate certain variables with low MEAN or ABSOLUTE discriminance measures. The best solution (from my subjective point of view) appear when I eliminate variables having MEAN DV
The leave one out approach is very helpful for my data set.
After that I applied the VARIMAX rotation and I can see the main discriminants on particular dimensions, even if % of variance explained doesnt change.
In relation to bootstrap - I use SPSS and as I know it doesnt permit to apply it on MCA or PCA outputs...
These rotations can be applied in PCA which is as I know not applicable for categorical variables . So instead of PCA I use Multiple correspondence analysis and till now leave one out approach was the most convenient for me.