Must be difficult to get back into it after a few years!
Of course, I am not familar with your data, so it is hard for me to say something about whether or not you can use 2 independent t-tests.
Let me say that people usually just do a t-test, and you can use a bonforroni correction to control for multiple testing (i.e., testing 2 related outcomes).
Anova is basically a t-test for more than 2 groups, so you don't need that (gender usually has 2 groups male/female).
Also, should I be putting these items in individually, or should I compute 2 new variables that take an average of each batch of items?
I don't understand this question, but if you mean: should I enter 10 + 3 vars or the mean of these:
Don't know what the reviewer asks of you, but usually if you have 2 scales you compute the mean of for each scale and then use these composit scores in analyses.