At this stage I guess my main questions are (still) - what can WaveNet Explorer do, what does it cost, and how do I obtain it ?

Wavenet Explorer is free and you can download it at www.pnpscada.com/wiki/WavenetExplorer.exe
The password is test
When running the program, you can press F1 to get the help page.
Wavenet Explorer is only used to setup the waveflows.
It does not have the ability to read the waveflows at specific intervals.
For that you will need an account on PnPScada.
You can use Wavenet Explorer together with PnPScada's TCP Bridge to program the Waveflows offsite.
Setup of waveflows include:
burst, leak and tamper alarms
pulse constants
synchronisation of totals with actual water meter
you can also read the 12-item profile from the waveflows (the new waveflows have 2000 items, but we dont currently support that)

For alarms from PNPSCADA:
The most important thing to remember is that the alarms can happen at any time and is communicated back to PNPSCADA at any time, without PNPSCADA requesting it from the device.
For this reason, the communication device linking the waveport and PNPSCADA needs to be connected at all times.
So this connection needs to be very stable.
Although there are 11 retries over a 2 week period for the alarms, should the communication device not be connected at the time of the alarm/retry alarm, the alarms will go unnoticed.
That being said, the way to get SMS/email alerts from an already installed WaveFlow setup, is similiar to any other meter.
For SMS, you'll need to create an account with CommunitySMS.com.
In PNPSCADA you can then go to Edit->Role Notifications to set which notifications you are interested in (for everyone in the role) and whether you want SMS or Email notification.
At the bottom you need to enter CommunitySMS.com login and password (if you want SMS notification)
Emails will be set to the email set in your login screen (for everyone in the role).
Also, under Edit->Login Notification, you can set which notifications you are interested in per login.