Zivush - 5:14 am on Sep 8, 2012 (gmt 0)
You can do everything but a reader wouldn't recall which widget you're talking about unless S/he digs inside this page :-)
(And I assume you weaken the main kw you're targeting for if not written in H1.)
The title tag is for search engines.
H1 is the title for the readers and for the search engines to value.
Regarding kw density that's my best assumption:
There's a big difference between reusing kw of 2 words and reusing kw of say 5-6 words.
Repeating a long-tail too often is a bad practice even for the readers, while 2 words kw can be considered a "term" and may pass the radar.
All in all, treat you site as a book with chapters (categories) and topics. If a reader can understand easily the meaning, by mentioning part of a phrase, so does Google. The only difference between a book and a site is that in a site, any page stands by itself.