1. I fully agree it’s a problem.
2. I don’t care as I rarely use trucks but where I do the wait for full load option works for me.
3. The ability to pick platforms for lines is needed because the game will often split platform usage unevenly. It would also be nice to be able to assign cargo to one track and express to the other where the tracks run parrarel.
Statement about how multiple lines on same tracks create a mess is wrong. A corridor that is made of two tracks, one for each direction of movement can handle many lines without any problems as long as junctions are designed properly by the player.
4. Wait for full load order works really well if used properly evidence in the screenshot: