There are a LOT of possible culprits in here. The excessive amount of scalar functions is certainly one of them. By my count there are 9 columns that are direct inline scalar function calls with a few more thrown into the joins and where predicates. I would be my hat that the scalar functions are the worst part of your performance woes. This level of scalar UDF means that your query is looking at every single row of these tables and given the names I am guessing these tables are quite large.

There are also a lot of variables in here (why are the names so generic?). I doubt you changed the variable names when you posted since all the rest of the information seems to be the real stuff. In general you will find working with code a lot easier if you give reasonable names to your variables. We have no idea what datatypes are here in your columns and all your variables. There may be tons of implicit conversions here too.