Hello,

I was wondering what is the best security settings for the Elgg 3.3.8, as far of the accepting new users that register themselves.

My site's settings are:
Users:
 Allow visitors to register,  (Yes)

New users require manual validation by an administrator ( No)
Allow user default access  (Yes)
The settings on the control panel, and if you think that it is dangerous because of spammers and others, or if there is a stopper plugin or not. 

I had it where I was approving, but then people try and never came back to fill up the profile. 
Another thing is that I want to upgrade but, i'm worry about my plugins won't work with the higher Elgg versions.
What could be your suggestion about the security of the site? Any ideas. Bookoflikes

@Book of Likes,

I would recommend you enable the plugin User validation by Email. this will make at least sure the users have a valid (working) e-mail address. There are other spam helper plugins here on the community which you could have a look at.

Updating Elgg with patches (so from 3.3.8 to 3.3.11) will always work without problems.
Minor updates (from 3.3 to 3.4) should work but require a tiny bit of testing.
Major updates (from 3.x to 4.x) will break everything and require extensive testing.