Share Point Server 2010 (SBS 2011)

Dear Sir,
                 i have installed share point server on my SBS 2011 , in this regards i want to clear some points .
kindly advice :-
             
1) if i make editing in my share point page through admin loging then will those changes apply on users also ?
2) I have assigned port 8080 to my sharepoint . although i can open it in my lan network , but not able to access from out side . i have opened the port also on my firewall . please do let me know the settings i have to check in my share point server if any . as i can open the link with same port internally.
3) as per my knowlege we can add modify important files and folders in sharepoint server .is it ? can you please specifiy in a list that what all we can do with sharepoint server and whats its actual defination ?
4) how should i create users in my sharepoint server with restricted access .
5) how can i take backup of my sharepoint server on regular basis ?
6) i can see microsoft sharepoint workspace option in my outlook 2010 , for what purpose we use it ?
7) can you please clear my concept that is there any difference of company website and sharepoint website ?
as we already have our company website , so what will be the use of sharepoint website ?
8)is document management system is one of the features of sharepoint server ?
do we have to configure document management system or by defaullt it gets configured when we install and configure sharepoint server ?
Kindly Advice
regards