The Portal site and minsites both work with a dial up connection, although like all other websites speed will be affected when uploading content and accessing the websites.
The client will be used to the issues of connection speed and where possible would be advised to get broadband.
MygroupNi generally train 2+ administrators per site to ensure back up if someone were to leave.
Where it is not possible to train more than one administrator we would advise that the person leaving pass on skills to the new administrator. The websites are built in such a way that allows quick and simple content management.
On many occasions community groups have requested a tutorial without training and have been capable of administrating the websites.
If someone leaves a group the group can decide a new username and password and change it straight away.
A manual policy could be put in place by yourself to remind all groups to change the UN and PW as often as you want.