does anyone here know how to weight keep-together restraints against one
another? I.e. if I have a keep-together.within-page on a table-row, a table
and a "section" I want to be able to give them different priority so that the
table-row is absolute (value="always"), must not be broken, the table is
second and the section third, but should still be kept together whenever
possible. I read that you could do this by giving integer values, but what
values? I.e. what is the allowed span? Is i 0-10 or 0-100 or what? Does the
maximum integer value equal "always"?

The spec is your friend:
  http://www.w3.org/TR/xsl/slice7.html#keep-together
Higher numbers are stronger conditions than lower numbers, and
"always" is stronger than any number, according to
  http://www.w3.org/TR/xsl/slice4.html#keepbreak
There doesn't seem to be a specific range if integers, inparticular
both positive and negative integers may be allowed. A specific
implementation however certainly will impose a lowest and a highest
number.