My history of finishing wood has been after building the project and painting it with some staining.  I am now working on refinishing some furniture and I need some guidance.
They are 10+ year old coffee tables with minor cracking where finish has split cracked and fallen off also there are a couple areas where the light  amber finish has a light color whitish ring from a hot coffee cup.
I have put Shellac, Varnish and Lacquer by dipping on some scrap wood in an attempt to find which is closest to the finish color wise. Shellac was too dark, Varnish close but to light and lacquer no color.
My questions are:
1. Can the refinish be done without sanding everything down first? Some of the wood may be laminate.
2. If 1 is yes what is the best way to proceed in cleaning, fixing the cup rings and finish cracks and general prep of surfaces?
3. What is the best way to determine which finish to use and get a color match?
4. I usually use a Nylon brush to apply these type finishes with a light sanding between coats. Would a sponge brush be better?
I know there is a lot to cover here but I would appreciate any help or suggestions.
Thank you