I don't know if you may like this idea or not. It still requires work, but it avoids spam and it does
not turn the site into a community. On the other hand, it doesn't exactly bring the discussions into public view.
The solution would be something like:
1. Add a very simple form that sends you an email to the end of each guide. This isn't different from what you already have in your contact page but it encourages contacting you right when a particular guide is read.
2. Add, again at the end of each guide, a questions section. Format this in a way that could be similar to actual comments.
3. Every time you receive a question, you manually -yes, that means work, I know- add it as a new comment/pair of comments in that section and update the guide if necessary.
Advantages:
- Avoids spam on the site
- Single source of truth
- Encourages readers to contact
- Allows for easier filtering. Nothing gets on the site if you don't actually validate -and process- it.
Disadvantages:
- Still requires work from your part, though not as urgent as "live moderation".
- Does not completely feel like conversations. Doesn't let different readers directly answer each other.
- It may result in you getting spam in your email.
- It's not automated. Again: Nothing gets on the site if you don't actually validate -and process- it.
Neutral:
- Doesn't shift the site into a community. I point this as neutral because it isn't bad per se but I understand that you do not want that.
I've seen this sort of set up work mostly fine. It does require work from your part, I repeat, but that really depends on how well it works -how much feedback you get- and since you seem to want that feedback to update the site, then the effort should be worth it.
If you go this route, one recommendation: In that simple contact form, set the action to something like mailto:contact@allaboutberlin.com?subject=... and include some identifier in the subject that easily links it to the specific guide they're sending it from.