It depends.

If gate 3 is permanently open, then with trespassing people could come in to the unprotected space between gate 3 and 1.
If the visitor gate is also permanently open, then they can either visit the outer rim of your base (without being able to commit crimes) or if you built a fence infront of the visitor gate, they wouldn't be able to enter, unless you open it. (Keyless)
In theory you could also give permissions to white to commit Theft on your property, without giving Trespassing and/or Rummaging permissions. They could take things you put in the outer rim (e.g. eat from a table) but won't be able to open the gates to the inner area without trespass perms.
If you opened gate 1 then it's possible someone might come into the inner and outer area without any visitor buff.
It's also recommended to have more than one gate, in your example someone could just camp in the space between gate 3 and 1, disabling you from leaving.