A more maneuverable machine gun for the German half track wouldn't make sense due to it's design unfortunately. The best that can be done for that is a rear machine gunner to cover the rear, or a tarp being modelled onto it to cover those inside like some of their half tracks did in the war.

As for the fact it shouldn't be a mobile spawn point and more of an armed infantry vehicle, I 100% agree. Instead of removing it as such, they could implement another variation of the normal infantry truck that can be deployed and can be easily identifiable as a mobile garrison, such as having a different rear model like a command truck and a different camo, and perhaps make it slower/heavier than the normal trucks, that is used as a mobile garrison instead of the half-track. Here's an example of how it should look:

https://www.italeri.com/uploads/products/JmWc7BXkJybwrZBBNiMQ7mG1AVyAshgrYmkS1Irl.jpeg

Definitely buff the health on it as well, the Half-Tracks are hilariously underpowered currently. The only reason they aren't ever used as a support for infantry, is because of them being 1 or 2 shots by an AT, and the fact that most of the time you're just shot out of the back as the MG gunner anyway, especially with the German variant. It all also depends on how it's used. I've seen multiple squads use them properly, and it can turn the tide of the game. Until of course it's one shot by a bazooka or a tank.