It's hard to say for sure remotely.
There were some cases when those units became weaker in 100 Volts network. Replacing the power supply unit solved the issue.
No. I think you'd better try to replace the power supply unit. You need one with 12 V DC, 1 A outuput.
"A" value may be higher than 1. For example, 12 V DC, 1.5 A is fine as well.
That's why I don't like the engine rumble effect
Yes, you should able to reduce its intencity.
As another option you could change the effect with customized .wav samples as we did with some guys in the Discord channel.
I'm afraid I don't know what is that. Never heard before about such a thing.
You've got 3 shakers. If you've got equal number of channels in the amps your choice is 3 - 6 bass-shakers option in the SimShaker Sound Module settings.
If you've got 2 channels in the amps your choice is 2 bass-shakers.
Yes, most likely you will want to edit samples containing "L" and "R" in their names.
Basically that's possible. It's not hard to edit the correcpondent sample in a sound editor as Audacity for example. You can keep the waveform only in the channel(s) where you need it.
But... as far as I'm concered the tubulence uses the very same sample as the ground bumps and the belly landing effects. Is it fine with you that those effects will change as well?
If not, I'm afraid some changes inside SimShaker for Aviators and SimShaker Sound Module code are needed.
The link takes you to SSA developer Github page and it looks like the latest version only is available for download there.
If you'd like to check the stuttering issue with earlier SSA version I can share 2.5.9.0 link https://1drv.ms/u/s!AtZazqt_Ko-7geBIrn0gcrroUGB9nQ?e=ftewRb