BBSHD and 12spd 10 - 50t cassette compatibility

I want to use a 12 speed cassette for my BBSHD 52v 28ah build. It is called the SRAM XG-1275 Eagle™ all steel Cassette 10 - 50t. This cassette fits on my 135mm frame so I am thinking that the width of the cassette is going to be close enough to an 11 speed so it will not mess up my chainline too much in the lowest and highest gear.

I will be using this bike to go to and from work so reliability is key for me. Is there anything else I should know or consider before buying this cassette. Thanks!!

Would it make more sense to get a lower speed cassette and a 3 speed IGH hub?

Do you think the (49t cog made of 7075 aluminum) on a 10 speed 11 - 49t cassette would break with 48t chainring, bbshd, and 52v 28ah battery ?

I want such a wide range of gears because I want to pedal at a cadence of around 100 at 30mph but also want to climb hills with a 10 degree incline without damaging anything.

With that kind of power I would not think you would need such a wide gear spread. My bike does 30mph in 8th gear at 90 cadence and up hills at 10mph at 90 cadence and it has an 8spd 11t-32t rear cassette. A 10% incline makes me pedal moderately to do 8mph but my battery is not giving me the full 750w of power (max of my motor) and we currently weigh 215lbs + bike. I would think yours would do fine. 11-40 gearing with a front sprocket sized to give you 30mph at 100 cadence in 1st gear would give you roughly 8mph in 1st gear at 100 cadence. the 10-50 combo with 30mph in high gear would be 6mph in 1st. I guess it depends on how much weight you are pushing.

you have to be careful with that motor and internal geared hubs, it puts out a lot of power. i am sure some of the veterans will chime in, I've only been riding for a couple of weeks

I would not use an Eagle for anything electric. There will bu too much stress on it.
There is a SRAM Wide range Cassette for e-bikes XG-899. But you should also do the math, unless you want very high speeds, I don't see why you would need such a wider range, especially as you state that you want to ride a cadence of ~100 (you should also check if the BBSHD is up to that cadence - I think yes, but I'm not sure).

I for myself run a BBS02, don't know my cadence (arround 80-85 I guess). Running the Bafang on a 12s battery suits my cadence quite well. The 11-32 Cassette gives a good ratio for me. Topping out at arround 50kph. I've never missed a smaller gear on the uphill, and I do ride steep ones.

This is a street bike, on an MTB I would prefer some smaller gears.