Those bits are grinding bits. For the CNC you really should use cutting bits. For aluminum, I have seen people have had the best luck with these https://www.amazon.com/dp/B07FSJLMJ5/

The motor upgrade might get you into a better speed range. The stock motors run at about 7K at full voltage. It is not so much the motor power that sets the 3018s back as is the rigidity of the mounts. Especially in the 3d printed Z-axis mount. The stock UU bearings are too short and have far too much play in them.

Given all of that, the 3018 can actually cut some things accurately if you take the time to tune the speeds and feeds to match the bit type. It's a great learning machine as well.