Page layouts  are exactly what the name would suggest - a template  to
control the layout  of the content  in a page. This doesn't have any
effect on the CSS for the items in the page, this is generally done at
the master page  level or via a custom CSS file in a publishing site
(which I'm assuming applies since you are asking about page layouts).
As far as getting the CSS for #2 correct, you have a couple options  for
getting better control over display of a Links list  without need to go
to pure HTML.

1) Convert a Link list view web  part into a Data View web part.

2) Use a Content Query web part with custom XSL

> This doesn't have any
> effect on the CSS for the items in the page, this is generally done at
> the master page  level or via a custom CSS file in a publishing site
> (which I'm assuming applies since you are asking about page layouts).

Hmm...not idea, but OK, good to know.

That said, could I, in theory, use the fact that it appears that
placeholders in a page layout  can override placeholders in a master page
to add a CSS link  dynamically to the page overall via a page template?
The key would be the ability to hard-code a default value in one of the
content columns  in the content  definition/page template.

> As far as getting the CSS for #2 correct, you have a couple options
for
> getting better control over display of a Links list  without need to go
> to pure HTML.
>
> 1) Convert a Link list view web  part into a Data View web part.
>
> 2) Use a Content Query web part with custom XSL

Custom XSL! That'd work! Good idea.

I'd have to try it to be sure, but I don't think it will work. I think
the CSS links  need to be in place before the placeholders are populated.