Workarounds?

Well, I have 3 things. One: what's a good wifi bluetooth solution that is known to work with macOS Sierra and newer UNDER 42$ (that's all I have, I understand it isn't a lot of money.)

Is there a workaround to get iMovie on 10.12.6? I was surprised to see that I couldn't get it (MacApp store is the only iCloud thing I have working besides actual iCloud. I have to wait two weeks for iMessage shadowban to be over before I can use it.

And lastly, is it true that High Sierra and Mojave don't work well with the GTX 660?

Specs:

i5 2400

8gb DDR3 1333mhz RAM

GTX 660

1 terabyte 7200rpm WD Blue HDD

I'm currently using ethernet shared from my laptop to use internet on my hack.

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