Some of the ability states are only available on certain units and since their part of the models themselves editing abp files sadly wont do very much. You can use Worldbuilder to see which states are available for a certain model.
Unfortunately it wont have either. A lot of the models left from coh1 don't anymore (probably cause their sound and visual effect files were deleted).
For the sound however you can try this workaround (though its not perfect)
Ok I didn't release their were different types of sga's. I suspect if it cant open them it wont be able to pack them either.
Sadly I don't know any other way to create them other then worldbuilder which isn't helpful for this.
Hi. You should be able to give it weapon by adding one of the mortar weapons into its combat.ext.
To give it an ability just clone any mortar barrage ability. Set up the actions like this
Then add it to the unit.
To be honest I don't think what your trying to do is possible as (apart from the Raketenwerfer) AT guns were never designed to be garrisoned, which is probably why yours is appearing invisible in the emplacement.
25 pounder emplacements work cause their attached to the emplacement from squad, which I don't think is possible with garrisoned units.
That's fine. The tools can be quite confusing. I have a discord if you would like more direct help with modding. https://discord.gg/yn3xa2a6
For the Brit Sniper when you say it doesn't show up do you mean the model doesn't visual appear? If so could post the ABP file so I can see if it looks correct?
Hi, in answer to your first question yes it should be possible by the editing the weapons attribute page. You'll want to change the duration in the setup tab and then change the settings in tracking/ normal tabs to a HMG to create a firing cone.
If you want to see the firing cone in game then make sure ui_setfacing is set to weapon default.
To answer your second question I need more information on what's not showing and what you tried to do to fix it.