Hi Muhammad,
This is in response to your second question. I would start by using a tool such as Xenu's Link Sleuth and run a report on your site. This will give you a report of how 'deep' pages are within your site ie. how far they are from your homepage.
As you might know, the general rule for most sites is to have all pages within 3 clicks of the homepage so this is a good way to judge the effectiveness of the site architecture.
Hope that helps,
Brendan.