It's exactly how Christina put it:

• keyword in title (the more keywords in title the better)

• title needs to make sense (as a sentence, not just as an enumeration of keywords)

• keyword closer to the beginning of the title it's a common practice

• keep it up to 70 characters long (google will truncate longer titles)

• also use your brand / site name somewhere

The example Christina gave is great, but to include even more keywords (and if you company is a local one) I would do:

"Top Rated UK Web Design Company - DR Adept" - as this would include the keywords uk web design company, top rated web design company, etc (combinations of all the words in there, you get the drift) - it won't rank as well for all of them, but it will be there.

To answer your question, YES, it has high trust and high authority so a link from that site would definitely help in terms of SEO.

The pagerank won't update. What you have now is what you'll have (probably forever). Good thing is that pagerank doesn't count. Your low DA/PA is due to the few links or low quality links you may have. If you want to increase it, you'll need more links (from high PA pages of course).

The only way to go is up, just make sure you keep your titles well optimized.