Official Luthiers Forum!

JJ,

Glue: Titebond is fine, and the moisture warping your bench is a non-issue. There is a zero percent chance that your top will be perfectly flat when you take the clamps off no matter what glue you use. So just glue it, let it set a day or two, grab a couple of your favorite beverages, and spend an enjoyable evening planing it flat (maybe less than an evening if you are faster than me).

Finish: I used Danish oil. Any other finish is asking for problems down the road. Sooner than later, you will need to plane or scrape portions of the top (whether you spill glue or something on it, marr it, or just need to re-level it). If your finish is oil, you just splash a little more on the scraped/planed section. Touching up varnish, etc. is more of a hassle.

Grain orientation: If you put all the grain going the same way, you will get less tear-out when you plane it flat, but you may get more warping over time and you may have to plane it flat more often. Personally, I alternated the grain for maximum stability. I get a little tear-out when I plane it, but not much. The tear-out never bothers me. However, I happily and regularly use my benchtop as an extremely reliable (and large) straight-edge.

Dogs: Doesn't matter. I like the square dogs, but it's not a big issue.

Two suggestions:
(1) Get The Workbench Book by Scott Landis, if you haven't already. A great resource.
(2) If you have a vacuum pump, drill a hole in your workbench top and put a vacuum fitting into the bottom of the hole. Put weatherproofing around the bottom of your radius dishes, and voila! your dishes are vacuum clamped to the workbench with a flick of a switch. (I keep meaning to do this.)

When I mentioned keeping the grain oriented in the same direction I meant along the lenght of the boards. The end grain will alternate something like this ()()()()()())(), opps I got one wrong, oh well the glues set. By the way, my bench used a half gallon of glue, get a glue roller.

JJ...yeah, I'm in the Titebond camp--MUCH less expensive than polyurethane or epoxy--and it will still last a lifetime and more. Titebond II extend will give you a longer open time, and it's water-resistant. Titebond III also offers you a bit more time than the original, and it's waterproof.

As for finish, I'd suggest shellac. It'll give you resistance to spills (doesn't really matter if it clouds or stains, in this instance) and it's easy to repair/recoat. Just get a can of Zinsser Sealcoat (2lb cut, dewaxed) or Sealer/Finish (3lb cut), brush on a couple of coats, and you're ready to use the bench tomorrow! Plus, anything left in the can is good to use for about 3 years! MUCH more convenient than oil, and less toxic/hazardous.