How to install .ipa file on arbitrary iPhone?

Question

iPhone

Good afternoon.
I study the issue of development for iOS and deal with Apple certification programs.
If I understand correctly, then Apple has two programs for developers:
1) Apple Developer Program ($99/year)
Under it, you can develop an application and publish it in the AppStore.
But at the same time, under it, it is impossible to launch the application on an arbitrary device in any way.
Question number 1: how to run the program on an arbitrary iPhone device without jailbreaking it, the name is only the developer account.
At the same time, it is impossible to find out the UUID of the device in advance (that is, you need to create an .ipa file so that anyone can take it and test it).
2) Apple Developer Enterprise Program ($299/year)
As I understood from the documentation, applications can be developed under this program, they cannot be distributed through the AppStore, but you can simply create an .ipa file with a specific certificate and distribute it to "employees".
According to

Manually Trusting an Enterprise Developer
If you send the iOS App File to a user and they manually install it on their device, then they must also manually trust your organization before launching the app. Instruct the user to follow these steps to trust your organization.

employees can manually confirm trust in the certificate, and everything will start for them.
Question #2: Is it true?
Question number 3: there are also rumors on the Internet that only one such certificate can be trusted at a time. It's true?
Question number 4: if I distribute this application left and right, how critical is it in terms of license and consequences?
Thanks in advance.

Answer 1

1. No. No way. A file is sewn into the application (ipa), which indicates the list of UDID devices on which it can be launched. At the same time, this file is signed by Apple, and cannot be changed.
2. Yes, it's called In-house distribution , and it works.
3. Rumors - I have several of these on my phone.
4. Depending on how impudent you will be. One such "cunning developer" (who even sold the service of signing an arbitrary application with his certificate) was banned and is no longer allowed to work like this.
And, yes, in addition to $299 a year, an enterprise requires a registered legal entity with DUNS and other amenities.

Answer 2

Link on the topic on the basis of which I built my question:
stackoverflow.com/questions/22227411/installing-ip...
It indicates that you must either
- have an Enterprise account and do not specify devices
- have a Developer account and an Ad-Hoc certificate, and list all devices
- have a Developer account and Distribution certificate, and install in the AppStore

Answer 3

You can test without buying a license. There is Testflight, through which you can distribute the test application to other people.