The min/max damage does seem kind of strange - especially since agents can apparently "dodge" bullets by using awareness, but if not dodged you're guaranteed to be hit no matter the range (provided it's within range of the weapon of course).

It would make sense if there were an ability/action one could take to delay reinforcements (which for all I know could actually be a thing later?) - but it's probably not needed.

The reinforcements make sense, and are needed IMO since otherwise it'd be too easy. They're definitely less punishing that XCOM2 Long War 2, and it's much easier (and much less frustrating) to maintain stealth, especially if you have an agent in disguise.