Stains are meant to penetrate the pores of the wood. The varnish seals the pores of the wood. Stain applied afterword just does not work well.
Varnish preserves wood better than paint.
A stain is used to color the wood while a varnish is a topcoat used to protect the wood.
Sometimes wood needs to be re varnished or restrained. To remove old varnish, you can use either a paint stripper or sand off the old varnish.
there are many ways you can. you can use a name brand stain remover, like SHOUT. or you can hand wash it with regular soap.
Wood wax is a type of varnish/polish
Varnish is to highlight and preserve bare wood.
Put a high quality stain or varnish to protect your wood flooring from scuffs and scratches.
No it is not safe to burn it.
you have to brush it
If it is cut into the wood, you will need to sand down the entire top to a point below the cuts, being careful not to penetrate any wood veneer (if it is veneered), then stain if necessary, seal, and varnish.
Varnish