I wasn't a moderator here when alfredm123's account was created. Blame Blast .

Ditto.

Feel free to chime in - not every post (as you probably know) needs to have some sort of technical information. We go off track so often you can probably chime in on every 3rd post.

From my point of view you already do a good job. Entering an arms race against the spammers will hardly be helpful. When the community supports the moderators by notifying about inappropriate posts, the problem should be manageable.
A few spam posts may be annoying but it´s something you will have to live with in a public forum. Maybe it is because of my time zone but I even fail to recall the last spam post I found here.

I would not want that to be done either. I have experienced forums were a monthly number of posts had to be made for staying in. The policy has an extremely negative influence on the quality. People just posted to chalk up the required posts. Towards the end of the month that tended to render the forum unusable.
Anyway people who do not post, do not offend or bother anyone. I am also in a HAM forum where registering for mostly reading members is explicitly encouraged. It helps the owner to judge the reach of the forum.