By default, a style-based TOC uses styles Heading 1, Heading 2, and
Heading 3. The TOC levels can be changed to link to any arbitrary
style under the "options" menu. Is there any way to make that change
permanent, for example, in a template? I haven't been able to figure
out anyway to avoid linking the TOC to my desired header styles each
time I create a new TOC in a new document.

As a related question, is there any way to change the names of the
styles used for the different levels of TOC to something other than
"TOC 1," "TOC 2," etc.., and to have that change also be associated
with a template?