SEO alt vs text

Question

I have 2 questions:

1 - Is there a difference in SEO between inbound links from the same site (from pages belonging to the same domain), and inbound links from other sites? are they the same value?

2 - is there a difference in SEO between (1) an inbound link with text inside it and (2) an inbound link with an image which contains an "alt" attribute with the same text and (3) an inbound link with an image inside it and a "title" attribute inside the link itself? like:

(1) <a href="http://www.[my-keyword].ext"&gt;my keyword</a>

(2) <a href="http://www.[my-keyword].ext"&gt;&lt;img src="" alt="my keyword" /></a>

(3) <a href="http://www.[my-keyword].ext" title="my keyword"><img src="" alt="my keyword" /></a>