OMG how I understand you. That’s exactly how I felt after first hours of playing TF.
After playing TTD and Locomotion in the past I had the exact disappointment you’ve got now. But somehow I forced myself to love this game, maybe because of lack of competition, or admiration of the idea, job and realization done by 5 Swiss guys.
Train Fever is not compatible with both things you’d like – a network, and fully loaded cargo trains. I’m not even sure why they put “wait for full load” option! If train waits, production drops.
When I tried to build a shared network, trains stuck, intervals became unequal, efficiency drastically dropped. The best way here is to have a dedicated track for each line.
It really depends on a person. If you want to accept the things as they are, or if you want to look for workarounds, or you don’t accept.
I’m a developer myself, and seeing how things are done I can say it will need a TREMENDOUS amount of development to alter the train navigation system and separate passenger and cargo principles (for the moment they are the same).
But @imajor, there is a workaround if you want fully loaded trains – modify wagons capacity, create (or duplicate existing) wagons, for different stages of production. OK game sucks this part, but these difficulties could make things funnier? And anyways, when the production will raise even my 25-wagon train will become fully-loaded, and more trains will be necessary…
And after all, seeing these trains roll, on a beautiful landscape, makes me forget all other issues..