SELECT with lots of left join is very slow in SQL Server 2014
It may be to do with the new cardinality estimator.  Try running the query with this disabled.  Also try the FORCE ORDER hint, eg

...your query
OPTION ( QUERYTRACEON 9481 ) -- turn off new cardinality estimator

...your query
OPTION ( FORCE ORDER )


I would also ask what foreign keys, indexes and constraints do you have in place?