Event receiver

Question

i have some doubts in event receivers.
when i do Itemadding or Itemadded, i frame like..
SPList oList = oWeb.Lists["Test"];
SPWeb.AllowUnsafeUpdates = true ;
 SPListItem oSPListItem = oList.Items.Add();
 oSPListItem["Title"] = "Hello SharePoint";
oSPListItem.Update();
oList.Update();
SPWeb.AllowUnsafeUpdates = false;
========================================================
when i do Itemupdating or Itemupdated..
SPWeb.AllowUnsafeUpdates = true ;
//i disable the event firing
oSPListItem.Update();
//i enable it again
oList.Update();
SPWeb.AllowUnsafeUpdates = false;
========================================================
when i do Itemdeleting or Itemdeleted..
SPWeb.AllowUnsafeUpdates = true ;
oSPListItem.Delete();
oList.Update();
SPWeb.AllowUnsafeUpdates = false;
========================================================
My doubts are
1) after updating an item , i am always updating the list oList.Update();
   Is it ok?
2) and while doing changes, which affects the content DB i am using SPWeb.AllowUnsafeUpdates = true ;
   Is it ok?
3)when i work on updating or updated event, i always disable the event before oSPListItem.Update();
   Is it ok?
4)when i delete an item, i am not updating the item, but i am updating the list
   Is it ok?

Answer 1

1) after updating an item , i am always updating the list oList.Update();
   Is it ok?-
I don't think you have to update the SPList item as you are updating just an item then SPListItem.Update should be sufficient to reflect the changes.
2) and while doing changes, which affects the content DB i am using SPWeb.AllowUnsafeUpdates = true ;
   Is it ok? -
Yes, this is Ok. But make sure you change it back to its original value once you are done everything in your code.
3)when i work on updating or updated event, i always disable the event before oSPListItem.Update();
   Is it ok?-
Yes, this is ok as if you do not disable the event firing then it will fire the updating/ update event as soon as you'll update the SPListItem through your code. Make
sure you will make the event firing enabled once you are done with your process in your code.
4)when i delete an item, i am not updating the item, but i am updating the list
   Is it ok?-
Yes, that is ok because when you are deleting an item from the list you are deleting an item from the item collection which is nothing but your SPList. So whenever you are deleting something you are updating the SPList which is nothing but the collection
of the items.
Let me know if you still have concerns.
#RoHsTr