Thanks again for your feedback, lots of useful notes here. I've been working on a patch which should also address several issues/bugs, thanks for reporting them.
Tutorial is being reworked, it's unnecessarily unbalanced and also the first squad should not attack immediately.
Armory ui bugs, units randomly shifting near other units bug, inf outlines in buildings, should be fixed.
I'm also taking a look at mission 4 - enemies should come to you, like you noted with the "last stand" sort of thing. I did decrease the difficulty so that may have thrown off the values which let you leave