MSDN documentation indicates that threads started by the TPL will enjoy better scheduling. However, since the threads are based upon ThreadPool, they will be implemented as
The TPL does not really give you Threads, it lets you create Tasks. Tasks can be executed on different threads, so Task != Thread.
As with the plain Threadpool, it would not be a good idea to change any Thread-properties.
But you problem could be easily solved by Waiting for any outstanding tasks from the main thread. You usually want to catch and handle their exceptions too.