Recommend table indexes and/or changes on a SQL Server query. Maybe indexed view.

I have a complex SQL Server query that needs a performance improvement. The query is the return of a function (ie, the function returns the query statement). I think that performance improvements on this query should be: indexes to be created on tables involved and create one or more indexed views (I know there are limitations, specifications and commands to be performed on the database for this, so if indexed view is to be done on this project, all these items need to be specified as well.) The file for this query is attached. The best description of the steps that are intended to be performed (as long as the price is good as well) wins this project. (I don´t need the solution on your description, just the prove that "you know what you are talking about" :) ). Thanks!