i just finished my bench. i had the same questions as you have now.
flatten it with a hand plane. start with a #5 with fore blade, and then switch to a #4 smoothing plane. that is REAL wood working. :D
for a finish. i used watco danish oil, i am happy with the results. but ...
my problems with that stuff are: (1) you don't really know what is in it, and (2) it's kind of expensive. i got a pint, and it was barely enough for 2 coats, and my bench is much smaller than yours
if i was doing it again, i'd mix my own rub, with turpentine, boiled linseed oil, satin poly, and some japan drier.
watco doesn't reveal their ingredients, but that is essentially what a danish oil is. change the amount and type of varnish to control the sheen and glossiness.
i would make mine with 2 pints BLO, 2 pints turp, a little poly (only 1/2 pint or less) and a little japan drier
this recipe is also pretty similar to what a rubbable spar varnish would be like.
that would make it easy to apply with a rag, dry pretty fast, and the poly would give it a little extra protection.
or leave the poly out and you have an oil rub.
Last edited by Chris Curl; 02-13-2013 at 12:35 AM.