If the filter is larger than the lens, that's fine. It just won't work the other way around, because the image on the wheels will be cropped. In addition, the adapter's job is to make larger filters usable on smaller lenses. 

Yes. Absolutely no problem. 

If the filter is bigger than the lens, then everything is fine. It just doesn't work the other way around, because that's how the image is cropped on the wheels. In addition, the task of the adapter is to make larger filters usable on smaller lenses. 

Could you please update us your full Minolta lens model ?as Minolta has MD MC and AF mount, K&F Concept MD-M4/3 is suitable for: Lens: Minolta MD MC Mount lens(not for Minolta AF mount: KF06.157) Camera: Micro 4/3 (MFT) mount mirrorless camera like Olympus PEN, OM-D series, Panasonic Lumix DMC-G1, G2, G3, G10, GX1, GH1, GH2, GF1, GF2, GF3, GF5, GH4, Panasonic AG-AF100 Mirrorless Digital Cameras, Black Magic Pocket Cinema Camera (BMPCC) 

In order to prevent vignetting, the ND2-400 is designed with an ultra-wide angle structure. The front port diameter of the filter is one size larger than the original aperture of the lens, so the lens cap needs to be one size larger than the lens aperture. For example, the 77mm ND2-400 Need to use 82mm lens cap.