This question has been answered by keymaster. See the first response.
If you remove any Resource Group Access ACL entries with a context of 'web', all the resources should be freely available in the front end. This shouldn't affect access in the Manager at all.
That probably has nothing to do with your script timeout, however, which is caused by some script taking too long to run. Do you have any complex getResources calls (maybe more than one on a page)?
The fact is that when the resource group is not created everything is fine.
But how i can restrict access to resources for the user in mgr without creating a resource group?