I am trying to export a site with subsites to a new site collection but because I am using hundred of custom features, lists, master pages & relative sharepoint things, I am getting many expection while importing, Looking for a alternative that will just export/import a site without validating anything
It isn't so much validation as it is basic SharePoint functionality. Custom Features and such can create any number of custom entities and if those entities do not exist on the site you are attempting to import it into, then it cannot be imported - by definition. The import/export process does not know how to create the entities, only how to use them. If you want to import the site elsewhere then you will need to deploy the custom features there as well. This is especially true of features that create Site Columns, Content Types.
If you are looking for some data-only migration then you may have to export everything to Excel/Explorer and than manually import it into the destination.