When you build a fighter the number of build fighters is also set to 0 after the production is added. If you simply select a new fighter and create another production, it is added with 0 as the number to produce.
This will be fixed at some point, for now you'll just have to re-type in the number, sorry. I know it's annoying.
When you want to release a ship with a tug into a fleet, the command releases the ship but as a separate fleet - not into the fleet you selected as a move-to-target. Maybe you can create a "release to fleet" task?
This workflow does need work for sure; the QoL is not as good as it could be.
On the 2nd tab of the Fleet Orders window there's a "Detach tugs when no longer needed" checkbox. You can check this box on the primary fleet.
Then you can tell the tug+payload fleet to join the main fleet, and the tug will be automatically detached afterwards. The only problem with this method is it creates a new tug fleet with an auto-generated name and none of the prior settings the old tug fleet had, which does get annoying.
The other option is to just release tractored ships at the primary fleet's location, and periodically manually merge them all together. This is still a step better than VB6, because you can release at the fleet's location rather than the colony's location, making it a little easier to find the target in your list of possible destinations. (for example, "Release Tractored Ships Miner TG" instead of "Release Tractored Ships Asteroid #6")
I have an ally which is sharing his grav and geo information with me. Recently I received a finishing message of a grav survey and wanted to redeploy my ship - but there was none. So the info came from the ally. I don't know but it might make sense to have those messages separate, or marked somehow that a survey finish came from an ally, not from your own ships and efforts. Or?
It's how VB6 does it but I agree it should be made clearer.