These are not necessarily "moving violations".
In what state is the limousine registered?
The loitering summons is a "hack" violation (I use the term "hack" loosely, here). The Harassmen-ER-uh-HACK Inspectors can, and do issue those all the time. If he can prove that he was OFF DUTY, it is likely that he can beat that one. Limousines must have a manifest, but that is only for their hourly trips. They do not need to put their Uber trips on the manifest. I do not know if a limousine must have a manifest when the driver is OFF DUTY. A taxicab driver must have a manifest when he is OFF DUTY and must note on the manifest the time and place that he went OFF DUTY. Drivers used to have signs for the dashboard, but now the third-world-taxi type light that they have has an OFF DUTY display. Do not get me going on that one; that is the subject of another post. Limousines never had OFF DUTY signs for the dashboard, although they used to have ON CALL signs that they had to display when they were waiting.
The "parking in a safety zone" is another matter. It is not a "moving violation", either. It can be a parking violation or it can be a "hack" violation. There is some debate as to whether a Harassmen-ER-uh-HACK Inspaector can, in fact, issue "hack" violations to an driver who is legitimately OFF DUTY, said OFF DUTY's being properly documented. I have seen it go both ways, although in cases like this usually it goes in favour of the driver. This is where my knowledge gap is critical, though, as I am not sure exactly how a limousine driver legally documents that he is OFF DUTY. If your friend can not legally document his being OFF DUTY, likely the summons will stand. Perhaps a letter from the limousine company on letterhead would suffice as proof. The Company Management might be loath to provide that letter, since your friend would not accept the "desperation" airport trip. As a rule, the Harassmen-ER-uh-HACK Inspector can not issue parking violations. The Police can issue any: moving, parking or hack.
I do find it curious that his insurance would increase over what are either "hack" or parking violations.
If you send me a PM, I will give you the address of a traffic lawyer who also does legal work for cab and limousine drivers. He is pretty good and his fees are not that bad (relatively). I have used him more than once, myself. Your friend may be able to deduct the legal fees from his taxes*, but he should check with his accountant on that one.
*I am not a Tax Professional, therefore I am not qualified to give out tax advice. Anyone who wants tax advice should get it from a professional who is qualified to give out tax advice.
