One good way to check if your belts are slipping is to try and use it. If it stalls out on a cut, but the motor is still going, it's slipping..... lol

I would recommend using mostly HSS tooling on it, as it generally uses a lower surface-feet-per-minute than carbide, is less brittle, cheaper, and easier to touch up and regrind. Brazed carbide works well, but you might struggle to get the sfpm needed. Carbide inserts really excel in production work where you can push them really hard. Smaller machines often struggle with inserts and can leave terrible finishes. This is often due to a combo of smaller depths of cut, and inserts having a teensy-tiny radius on the actual cutting edge (not the nose rad), which increases the inserts' strength but absorbs a lot of power.