Can I ignore queries about extendedproperty?
You can modify this behaviour by changing the scripting options:

Tools -&gt; Options -&gt; SQL Server explorer -&gt; Scripting -&gt; Script extended properties


 


  Is there any important data or settings in these queries or I can completely ignore them...


It depends.

DBA's and developers can use extended properties to save information about database objects. If you're scripting other dba's objects you could loose information about them. 

Have a look at this articles on MSSQLTips:

Working with SQL Server Extended Properties

Quoted from doc


  Extended Properties can be created for the below database objects, but
  in this tip, we are going to focus on column level Extended
  Properties.
  
  
  Database
  Stored Procedures
  User-defined Functions
  Table
  Table Column
  Table Index
  Views
  Rules
  Triggers
  Constraints
  





  Extended Properties can be used to:
  
  
  Specify a caption for a table, view, or column.
  Specify a display mask for a column.
  Display a format of a column, define edit mask for a date column, define number of decimals, etc.
  Specify formatting rules for displaying the data in a column.
  Describe a specific database objects for all users.