Well, yes: the store does advise caution, as we have little control over themes and widgets uploaded by their parties. The same way we would advise caution about running random software downloaded from the internet. That said, it does say KDE Store, so we should have some degree of control over it for our users’ sake. That is what we are working on.
That said part II, we can’t do with it the wider communities support. There simply isn’t the human resources necessary. The 2 options we have are to close down the store completely (but then people will just go to random GitHub repos and download stuff from there), or try to leverage the community to help us locate and remove (or at least quarantine) dodgy products.