Morning
With all due respect, I'm not sure I understand all this, obviously it's your site and you do as you like, it's just a forum but the amount of work that must have gone in to changing the site from the old format to the new, the ongoing issues and complaints, now you're working on adding comments, it seems crazy to complain about the amount of work it takes to moderate a forum.
I read the comments about how the b&s section has similar traffic and all that but I just don't see it, there used to be hundreds of adverts, you could post something one day and the next it would be down to the second or third page, it was lively and I often found things I didn't know I needed, not good for the bank balance but good for the forum. Now it looks like you get a couple of ads a week, what are you making from that? Honestly, it can't be anything, Bob's time to get the forum changed to this system must have taken ages, the 4 adverts for April so far aren't going to make you any money.
I understand the moderating issues but that sort of goes with the territory doesn't it? No point starting a forum and then complaining that it takes work to keep things on track, why not just recruit volunteer moderators? Some forums have 1 or 2 moderators per forum section, it's not a full time job, just some people you can trust to be fair but step in when things go to far, shouldn't be that difficult and shouldn't cost you anything.
Ultimately it's just a forum, not worth getting stressed over, if people really prefer the FM selling forums then sell there, it doesn't really matter in the big scheme of things. If you were still getting the volume of adverts you had previously, they were being paid for and people weren't complaining about the usability then you'd be on to a winner but it doesn't appear that any of those things are happening, all you've done is reduce the b&s moderating needs and thrown the baby out with the bath water.
Good luck, I don't envy your task!
Mat