No, the integrated hard stops prevent the filter from rotating beyond its calibrated range, effectively eliminating the 'X-pattern' cross-polarization common in budget variable ND filters.
This specific model is 82mm. To use it on a 77mm lens, you will need an 82mm-77mm step-up ring, which allows one high-quality filter to work across multiple lens sizes.
No, the use of high-definition optical glass and multi-coating ensures that there is no noticeable loss in sharpness or color shift, even when shooting at 4K or 8K resolutions.