None of the tweaks mess with sleep.
What it sounds like is a program is keeping the system to stay out of sleep mode. When it does go into sleep mode any of the tasks in the task scheduler are normally set to bring the system out of sleep to run the task, that might be where you find why it keeps coming out of sleep.
As for your system not showing on the network during sleep. That is what is normally suppose to happen. Sleep mode is where everything shuts down to a low power state. Hibernate is simply a more advance version where everything in memory is store to the drive and its dang near off.
You can set the network card int he device manager to not power down during sleep. That might keep it on the network during sleep mode
Shane