Its the same as banning them, they can log in, but all they will see is a message in the center of the screen saying "You are not allowed to visit this community" they will get that on every page they visit.
I don't think you will get an answer, as most users that show as a non client, get told to log in to their client account. Otherwise they could be using a Nulled script, as some users here don't like helping people that are using a stolen copy, I am not saying you have, but thats the way it is most of the time.
If you can talk to the License owner ask them to add you as an "Alternative Contact" in the client area, that way you can submit support tickets to IPS, and get a better answer. I am not sure, but it might also allow you to access the support section on these forums.
same here, but I guess if it is going to be later than May/June, I will have to launch that without 4.0 (many features need 4.0, even more so now due to the news on IP.Connect, as its not just 1 site, but a network of many.)
Honestly I don't bother with IPS Spam Service, its ok, but Stop Forum Spam plugin works a lot better. I have used that on my board 12,436 Total Members and only 30 are banned, and only 5 of them were spammers, rest were banned for breaking rules.
Edit: Then again I haven't used the spam service for the last year and a half, could have been improved since then, but I am currently sticking to StopForumSpam.
The search engines / guests see content in most of the sections, except the members only section, that one has the "please register to view this section", that shows guests there is more to see if they sign up.
I create and display Forum sections just for Validation group and call them "Validate Your Account To Access This Area" then in the description of that section add a URL to a page, that explains what to do, and how to do it.
Also do the same for guests, saying to view this section register for a free account.
EDIT: forgot to add that I set the system to automaticly delete accounts awaiting validation after 14 days, thats plenty of time for them to activate their accounts, if they don't bother then they are not worth the space on the site. Would rather have a small number of members that are active and post a lot, instead of having loads of members but only 10% post.