SEO question

[sarahbrooks]

Hi guys! I want to share some basic seo questions..

1. what is the limit for keywords for each page?
2. what is the limit for title characters for each page?
3. what is the limit for description characters for each page?
4. does it important to use <strong> and links in content?
5. does it matter to name all photos on flickr and picasa accounts?
6. how important to update website on regular base?
7. how important link exchange (tricks)?