Need help with mining basics, page-2

You are on the right track!

Essentially correct - the hole enters the mineralised zone at 330m

"Consistent" may be a bit strong... but yes the average grade for the interval is 0.60% Cu and 0.53g/t Au.

This is an example of the variability - and given they have highlighted it this is one of their better zones.

Again you are correct

There are two primary types of drilling that would be able to generate those results - RC and diamond.
With RC drilling the cuttings from each meter drilled are collected and bagged. These cuttings are sent to an assay lab and a representative sample taken to be assayed.
Diamond drilling produces a "core" of the hole drilled (like an apple corer). This core is cut in half with one half kept and the other send away for assay.

Exploration holes are typically drilled at an angle and designed to cut through the mineralised zone. They won't often be at right angles to the mineralisation hence the need to calculate true width based on the angle of the hole to the dip of the mineralisation.