@Summer127 I agree with Emiel that it's a really bad idea for new hosts to take long-term bookings, its actually not a great idea for a lot of experienced hosts, either, who've experienced problems with this.
What are you missing? Well, unfortunately, a clear understanding of how Airbnb works and what you can and can't do when listing with them.
All the requirements you are asking of your guest are not things you can ask of them when listing on Airbnb, but of course they are the standard things that regular landlords ask of guests when considering renting to them and which you could request if you were booking guests directly through your own personal website.
Guests pay according to the policies of Airbnb, and if they cancel, you are paid according to the cancellation policy you have chosen. You can't just set your own terms of payment and refunds. Also, Airbnb can and does refund guests according to their discretion, so don't be under any illusions about that.
Regarding the guest photo- hosts have no way of knowing if a guest has submitted a profile photo of their face when getting a Inquiry or a Request, because guests' profile photos are hidden from hosts until a booking is confirmed (supposedly to cut down on discrimination, so a prejudiced host couldn't reject someone based on the color of their skin, race, etc.). So you can't make the assumption the guest hasn't done this, you just can't see it.
If you have profile photos checked in your settings for guest requirements and you see the guest hasn't provided one after a booking is confirmed, then you can ask them to upload one. But be aware that when Airbnb asks guests for profile photos, they don't care if they post a photo of a plate of spaghetti, their cat, or a cartoon character. So if you want to see a real photo of the guest, make sure to note that in your listing ad.
Also, you need to be aware that anything you require of guests needs to be mentioned in your listing description- you can't just spring things on them that weren't in your ad. So if you want to be able to ask guests for photo ID when they arrive, to ensure that it's the same person who booked, make sure to state that in your listing info and also reiterate in a message to guests. Airbnb can delist you if a guest complains to them that you sprung requirements on them that weren't mentioned in your ad.
So best you learn the ropes a bit (which this forum is awesome for- read some here every day if you can, not just come here when you have a question or problem- it can alert you to and prepare you for so many issues hosts have to deal with) before looking at taking on a brand new guest asking for a long-term booking, with no reviews and no information.
But I will say that your idea of having a "trial run" booking of a shorter period of time to find out whether it's a "good fit" and whether they will be good guests or not is, in general, a sound one.