Given that Long Covid can be due to persistent low-level viral presence, can the SARS CoV-2 virus lead to malignant transformation and thus represent a cause of cancer or other maladies?

This can theoretically happen, but is relatively rare, thankfully, given the natural healing potential of the body. There is an ongoing surveillance by the immune system on the watch for malignant transformation, so as to remove the wayward cells before things get out of hand through out-of-control proliferation and spread. That usually takes care of short-term sources of malignant transformation, which will often accompany infection and other insults that stir up immune responses in some way. The collateral damage from inflammation, in particular, is a major culprit in setting people up for virus-caused maladies of many kinds.