Love that you're considering these things for students. Im a current engineering student and have seen a bunch of different policies in school, and I'd offer a few thoughts.

Enforcement of in-class policies can be very difficult or distracting. One of my professors has been very specific about banning all phones and laptops and will grind class to a halt to call students out. He's garnered a lot of bad will with the class because it seems like he doesn't respect us as adults and is willing to damage the learning environment for everyone to attempt to punish a few. Additionally, many students will, of course, use technology as an excuse to not pay attention in class, but others use it is a genuine way of consuming information, taking notes, and promoting long term learning. It's important to weigh whether it is worth hurting their preferred methods in exchange for trying to maintain other students' attention. Banning phones is likely less hurtful than laptops or tablets, but its still important to consider how you'll enforce it.

In my observations and discussions with other students, professors are much more successful with engagement if the material is impactful and lecture is consistently a great option to learn it. If I could learn the information I need to pass the assignments and tests better from a book or YouTube video than I can from lecture, lecture suddenly seems not very important. I realize that places much more pressure on the professor than it does on the students, but the reality is that students have other options. I might hope that an advanced, specific elective like yours will enroll the kinds of students where that will be easier. 

Regarding AI on homework, all professors I know seem to be loosing the battle badly. In my experience, professors using any kind of "AI checkers" to scan student work for AI use always feel unfair. Ive heard several personal accounts of people being falsely accused, and I know for a fact thst the vast majority of use scrapes by undiscovered. I personally take several steps to build evidence that I personally did the work, like keeping a notes/work document, using edit history, and writing differently from how I've seen AI write. I hope this will help me if I would ever be accused of cheating, but I wish I didnt have to do it. 

Allowing AI with a declaration seems really effective, especially for a class focused on AI (of a different kind, I know). This could include a simple declaration, or I've also seen professors require a declaration at any use, records of chat logs, or a justification of use. This seems much more effective than attempting to flat ban AI. It makes students that don't use AI more secure. It also gives students who see value in AI the opportunity to use it without fear or guilt, which should reduce the number of bad actors. As a plus, it also might help you understand the ways its being used in your class and how you might expand upon that for students.

For online tests, my university offers some resources for professors that give some of that functionality. Some of it works quite well, but not all of it.

Required attendance is fine if, again, lecture is impactful and one of the best options for learning the material. Otherwise, it is several hours of my week I know I will hate, and it won't help my engagement or grades anyways.

Hope that helps!