It seems to me that the 'System' makes every effort to protect them. What it can't protect them from is a pilot prepared to break the rules he knows he's supposed to obey, but which he knows can't be easily enforced. Short of matching the pilot's DNA against a database and remotely inhibiting the engine until everything checks out...what can the 'System' do? Ultimately it has to come down to the pilot's personal values system.

Do pilots need to be chipped, like pets?

Medical
 

61.75 doesn't actually say " all operating privileges and restrictions associated with the UK PPL must be adhered to whilst operating an FAA 'N' registered aircraft" but that may be the intention and the normal interpretation. What 61.75 says is " (3) Is subject to the limitations and restrictions on the person's U.S. certificate and foreign pilot license when exercising the privileges of that U.S. pilot certificate in an aircraft of U.S. registry operating within or outside the United States; and....."

Does a UK PLL for a pilot with no night rating have the text "Day VFR only" or "Night flying prohibited" or some similar limitation or restriction?

From the BBC re recovery;
https://www.bbc.co.uk/news/uk-wales-47129137

Yes it does; an EASA or UK PPL requires an individual rating for each of the following, flying at night, flying in IMC, flying IFR in controlled airspace, therefore if the FAA 61:75 licence is issued on the basis of a basic UK or EASA PPL with no night or instrument qualifications then the FAA licence is also only valid for Day VFR Only. As ratings are added to the UK/EASA PPL then you can apply to the FAA to have the privileges applied the FAA 61:75 licence.

In actual fact the original concept of the FAA 61:75 licence was to allow non US citizens the opportunity to fly 'N' aircraft while visiting the USA on say a holiday were they wanted to do some solo flying and was valid for use only within the 48 states of the US, this I believe can be extended for use outside the USA with a BFR.

It is incumbent on the regulatory authority to monitor and ensure compliance with the regulations with which it is entrusted. This particular incident raises the issue whether the CAA was effective in such measures it had in place to effectively carry out its remit. I believe it is more likely than not, this incident may lead to closer monitoring of private flights in light aircraft operated outside the strictures of AOC by the likes of PPL holders. This will involve seeking to inspect how "actual cost" has been ascertained.
Here is an extract from CAP1590:

5. EASA Ops includes a derogation at Article 6.4(a) that allows a flight that would otherwise be a CAT flight to be flown in accordance with the operating rules for non-commercial flights subject to specific conditions. The conditions are that:  The flight is a cost-shared flight by private individuals;  The actual direct costs of the flight must be shared between all the occupants of the aircraft, including the pilot, up to a maximum of 6 persons; and  Only other-than complex motor-powered aircraft may be used. 6. Article 13 of the ANO also allows cost-sharing for what would other......

Note in particular " only other-than non complex motor-powered aircraft ". Its been some time since I have been around club flying, but if my memory serves me right I would have thought a PA46 would fall under the complex category.

Also it must be noted that the relaxation is by way of derogation, one always needs to be so careful with that sort of permission.

A lot of coverage regarding FAA pilot requirements but I wonder how the FAA maintenance requirements were covered for the N-reg pressurised aircraft?

I don't see anything in 61.75 that would allow an instrument rating to be added unless the applicant had an instrument rating on the foreign licence. What regulation allows that to happen?

If it is allowed then what would be the path to get the UK day only restriction removed, remembering that there is no FAA night rating?

I can categorically assure you that this is not (always? often? even ever???) the case. I know personally of two occasions when desperately serious cases were reported with full corroborating evidence available and no action was ever taken. Plus several other additional incidents related to one of the aforementioned that I've been told over the passage of many years by utterly credible people were also reported (making a whole stack of decades long accusations against one operator) with no effect whatsoever.

Don't be fooled. The CAA enforcement system is an empty fraud. No more, no less.

It would be 61.65. It only says you must hold at least a current PVT certificate. It doesn't say it can't be a 61.75 certificate. FSIMS goes a bit deeper into adding additional ratings on a 61.75 cert. You would still have the FOREIGN BASED notation but if you complete the normal training and checking for an additional rating it would be followed by U.S. TEST PASSED.

There isn't any. Since as you point out there is no FAA night rating there is nothing to add. It's been suggested a foreign pilot could complete the 3 hours and 10 landings required for a PVT cert and then get a 90 day student night solo endorsement.

Blackfriar
 

"This accident, like so many before it, was caused by the pilot’s decision to undertake the flight in which the likelihood of encountering instrument conditions existed, in the mistaken belief that he could cope with en route instrument weather conditions, without having the necessary familiarization with the instruments in the aircraft and without being properly certificated to fly solely by instruments."

Civil Aeronautics Board Aircraft Accident Report on the "Buddy Holly" accident, released on September 23, 1959.

Useful site: https://lessonslearned.faa.gov/index.cfm

A licence issued under 61.75 is a perfectly valid licence in its own right. Where a 61.75 licence holder passes a US IR Check Ride and completes the US IR written, the 61.75 will be endorsed with the phrase "INSTRUMENT AIRPLANE U.S. TEST PASSED".

Where the 61.75 licence holder has an ICAO instrument rating on his underlying licence, he can also validate that onto his he US licence by passing a cut-down version of the US IR written aimed at foreign pilots (known as the IFP). Whilst there is a little inconsistency on licence endorsements, the standard licence endorsement goes along the lines INSTRUMENT FOREIGN PILOT TEST PASSED

Absolutely correct! An FAA PLL 61.75 is a license on its own and handled as such. Some more:
If you validate an ICAO license to get an FAA 61.75 license, the only thing granted is PPL rights.
You add additional ratings and endorsements on the FAA 61.75 as if it would be a new license.
Experience from you foreign license will be evaluated and you may get easier access or waivers of exams for certain parts, i.e. for an ICAO IR to do a fast track FAA IR test.
Sometimes they grant fast track evaluation on first validation if your ICAO license already has additional ratings, i.e. IR, but this is not for sure.
A FAA 61.75 based on foreign license is not compatible with a 3rd class Medical, as the US easy access medical is non-ICAO standard, the pilot needs a valid ICAO medical on hisherit original license to fly.