You are definitely on the right track. Here are some suggestions from someone who has hundreds of orchids, in every conceivable pot/basket.
Rather than having your holes sort of in a line across the pot, stagger them from top to bottom. The idea is for air to reach as much of the orchid medium as possible. I would also (at least) double the size of the holes and rather than just having round holes, since you are creating these pots yourself, vary their shape. This makes for a more interesting pot. So lots of large, irregularly shaped holes.
I love my orchid pots that have built-in saucers. Here's an idea. Build your saucer with a raised platform, a platform that the orchid pot sits on. But when you glaze the pot/saucer, have the pot sitting on this platform so that it becomes a single glazed object. In other words, you don't want the saucer separate from the pot. This would raise the pot above the level of any standing water. Thus the water-filled saucer would increase the humidity around the plant. You never want the orchid pot to actually sit in a saucer of water. Im my humble opinion, over-watering kills more orchids than all other reasons conbined.
If you like I can send you some pics of what I believe are ideal orchid pots. Ken
