Rub it with a rough rag and Goof Off, it will soften enough to be peeled off.
you cant
dampen a rag with lighter fluid or mineral spirits. no you wont remove the polyurethane, its dry. but it will however remove the glue with no problem or blemishes in your poly.
If you mean the glue that hold the vinyl to the floor there is an alternative ask your local vinyl supplier about vinyl designed to be "loose layed".
Yes, you can use wax.
Laquer thinner .
It is possible, but it's not the best practice. If you can easily remove the existing vinyl, then do so. If the vinyl won't peel up, then you should consider two possibilities: Remove the vinyl along with the wood underlayment (or scrape it off if your subfloor is concrete), or install new wood underlayment on top of the existing vinyl.A third possibility is this: If the existing vinyl is securely glued to the floor, you could apply an embossing leveler (cement-based product) in a very thin skim coat over the vinyl. This seals in any stains, levels the floor, and gives the new vinyl a nice, smooth surface to lay over (or a good surface for vinyl glue to adhere to).Most flooring manufacturers will not honor the warranty on their vinyl if it is installed over existing vinyl, unless you do the embossing leveler step above.
The best thing to use to remove aerosol residue from a vinyl floor is baking soda and water. Lemon juice can also be used.
Use Goo Gone, it will remove it.
If it has a timber floor under and vinyl is solid to the floor and not to thick screw down 10 mm ply at 150mm centres. seal ply with pva sealer prior too tilling. If it is a concrete floor it is best to lift vinyl.
Cant be done sorry
Poly vinyl acetate is white glue.
If it is a deep scratch you cannot usually remove it. Sometimes if a scratch is somewhat on the surface then a floor stripper might remove its appearance.