1) Pulse Premier includes SERVICE for two cameras for $60/month. Local promotions may change this. Additional cameras and service cost extra, usually ~$120 per camera and ~$20/m for service.
2) Up to 30 days retention is max. Cost seems to vary on this point but it is at least $100/m.
3) Only 'Pulse' branded cameras can be used (from Sercomm), and both performance and flexibilty are modest. Definelty not 'professional grade'.
4) I've seen the Pulse app, it seemed easy enough to use. Of course programming takes place online or via installer, but most functions could be easily reached.
5) Pulse uses it's own router and/or GSM module. It's not plug 'n play in a general networking sense.