Yes this indeed is an issue and one that should be default functionality and fixed, you do not need a 3rd party plugin for sub categories (this is an excuse)
The first thing that needs to be fixed is to show sub categories when the main category is clicked.
The second thing that needs to be fixed is the padding left issue
And finally the product count is not styled correctly and not in the correct location
I can fix this myself but i should not have to spend that time fixing it.
The developer has been helpful to me so far and fixed a couple of issues but this is just another example of a theme that has not been tested thoroughly and released with problems.
I hope support resolve this issue a.s.a.p or at least tell us what css needs to change and we can do it ourself.
Thanks.