That made me have a blast from the past:   Yes, maybe some things could be made more distinctive, it would confuse me at the beginning, the problem is that one gets used to suboptimal stuff to the point of forgetting it (like ridiculously small font size).      

Not necessarily, for example if you are "housed". Things like building a house or researching population bonus techs would kickstart many stuck production orders at the same time. You have to check if that could be the case, although I'm assuming probably not if it happened constantly.

When I started playing the game I also wondered about the food icon and that it might put off some people, so, as expected.  Personally I'm not vegan, but I also think, for the standard game, a wheat icon would be more representative, because arguably, most food in most cases comes from working the fields. And it's pretty standard in other games too (Civ etc). Now, distinctive colorization was  mentioned somewhere as an argument against the wheat symbol. Not so convincing to me because the wood's brown is quite in the middle between yellow and red in color space. Also there are a lot of similar problems in 0 A.D.'s iconography. Docks, Barracks, Storehouse icons are hard to distinguish, color-wise. I still need to read tooltip distinguishing FIeld from Farmstead etc

I had a staff lineup, but I need to develop the idea further. The staff needs to be upgradednor gain experience. Based on that personnel, the ship gains different stats.

I'd bet it's ModernGUI's smart training system, or some other variant.