There isn't any wood finish that is waterproof, all is water-resistant to some degree but I wouldn't leave water sitting on the top for too long. If you want waterproof you need epoxy resin. Same with heat.
Nothing is perfectly clear. Oil-based finishes tend to have a yellow hue, water-based finishes tend to have a blue hue.
If you send the edges well, splinters shouldn't be a problem with any finish.
If you want to see the grain, don't paint it.
If you want a wood feel, leave it wood.
Most finishes come in different sheens.
Finishes have different resistance to scratches, but all are susceptible if treated rough. Resin epoxy can be very hard.
I wonder if the OP is ever coming back?
Nothing is perfectly clear. Oil-based finishes tend to have a yellow hue, water-based finishes tend to have a blue hue.
If you send the edges well, splinters shouldn't be a problem with any finish.
If you want to see the grain, don't paint it.
If you want a wood feel, leave it wood.
Most finishes come in different sheens.
Finishes have different resistance to scratches, but all are susceptible if treated rough. Resin epoxy can be very hard.
I wonder if the OP is ever coming back?