Disposing SharePoint Objects

Yes. It's completely fine.

If you can use like below code in using block:

using(SPSite oSPsite = new SPSite("http://server"))

{

  using(SPWeb oSPWeb = oSPSite.OpenWeb())

   {

       str = oSPWeb.Title;

       str = oSPWeb.Url;

   }

}  

web.Dispose();

site.Dispose();