That is true for trades between neighbours and friends. Trading between guild members is free of charge.
The forge point bar accumulates up to 10 forge points which equals 10 hours. This does not mean that you must spend these 10 forge points at once, for one single thing only, e.g. research. You can choose to donate a certain amount of forge points to a technology and the rest you can spend on trading if you are not in a guild.
As for not earning
enough to trade -that is up to each player individually - how many trades do you want to accept? 2 or 20?
Every person has a different style of playing and chooses to focus on different things - some prefer to be as much self-sufficient as possible, others rely heavily on their guild members for the goods they need, which works out well because, once again, guild trades do not cost a single forge point.
I have re-read my post and I don't see where I have said/implied that you must limit yourself to your tech tree. I was merely asking how it was possible for you to not produce a single forge point when you have progressed in the game and are in the Iron Age - for which you need forge points.
Also, you can buy forge points with coins. So, even if your acculumated forge points
all go to your tech tree, you can still accept some trades by buying one or more forge points. This is just a suggestion - I am trying to cover all possible scenarios here.
How can you maintain that this is a bug, when everybody else is playing the same game and has not once managed to come across this 'bug'?