Way to be on things Dave, nice to see ya zapped the "like" button already. I honestly think that is a good step forward IMO.
I'm no site guru but I have helped run a number of successful fishing and rod building sites over the past 10 years so I'll just toss out a couple other things that I feel helps to get a site active.
One thing to try is to condense the number of forums as much as possible. Reason for that is because if a potential new member comes here and looks at a whole wall of 20+ individual forums on a site and lets say there's only 5 of those forums that have new topics at a rate that is anything close to often, then that person is going to think to themselves that 75% of the site is dead most the time and they will end up not joining. So it's better to have less individual forums on a site that are active, than more forums on a site that sit for days or weeks at a time without a new post icon next to it. It just gives the "look" of a more active site to potential members is all. So if there' some forums on here that could be made sub-forums, or combined with other forums then I would suggest trying that as well.
One other thing to do is rotate through the moderators each week giving the mods the job to start some new topics. Here's what I mean by that...and I can't remember whom all the mods here are so I'm just gonna pick a few fake names...
Lets same your mods are Johnny, Jake, bob,and Larry. In the Mod forum set up rotation list like this...
This week- Johnny, next week, Jake, 3rd week Bob fourth week Larry. When it's your week then that mod needs to dedicate a little time to searching the internet for what ever is the latest gaming news then starting up a few posts about it. Same with the next weeks mod, and so on and so on. Obviously you don;t want to start a post that is pointless or lame, but it shouldn't be that hard to find some relevant gaming news that people would like to hear about and discuss on a gaming website. And it would only take a few minutes each day for the mod who's job it was that week to start some posts.
We did that on some of the sites I run and it worked very well. Then after the first year or so of doing that the sites were active enough with enough new people that we no longer had to have mods kick start things and the sites kept going on their own accord.
Anyway, just a couple suggestions.