The effect of any particular oil on your engine is really hard to quantify. The oil debate is one that always generates dozens of pages of discussion, because everyone has their opinions about oil. In the end there's no real black/white answer to be honest.
There's a number of failure modes for oil. Time at temperature is the most important one. Shear stress is another. Granted, any oil that meets the official spec should work in the car. But since the OE oil is what was used in the development and validation of my car in the design stage, and I know it has the right physical properties and additive package to work with the rest of the engine system and materials, I stick with OEM.
I have zero experience with the oil brand/type you are mentioned, so I cannot offer up any comments. You might be ok, especially given your duty cycle seems to be fairly mild/medium. Then again, if the oil degrades quickly, you will start to see increased wear of bearing surfaces and sludge formation. But at a minimum, I would pick something that BMW recommends:
Anything that doesn't meet this, I would be leery about.
On a different note, have you thought about the filter? If you plan to stick to the normal ~15k mi interval, remember that you will be taking a huge risk with a filter that's not OE, or made by one of the OE suppliers (Mahle, Hengst etc.). The filter element gets the full pressure of oil and sees sustained temperatures over 100C long-term when you're driving. The filter element is also designed carefully to trap particles above a certain size. Aftermarket filters may not perform the same way for longevity or filtration. I've seen a lot of paper elements torn or crushed that I would hate to have inside my engine. So pick the right filter that's known to reliably work in your car..