Yes the 24 is a smoker, but the 35/36 is not a puppy dog. It will still bite you if you don't pay attention. Compared to the 23 and 24 the 35/36 is fairly tame, but compare it to other bizjets like the Hawker, citation or Falcon, it is still can be a handful.
There are very few Lears out there with the razor wing, I have seen that particular 24 and I can't recall what wing it had. But I think I would have noticed if it had the razor wing. That generation aircraft, most likely had the Mark II wing.
The 20's do accelerate quickly and the pilot has to be well ahead of the aircraft. The 35/36 is slower due to the fan engine, but they will exceed Mmo if you let it. This is one thing that 20 drivers have a problem with, the slow acceleration of the 35/36. They want that quick acceleration and will level off too early to get it.
The autopilots will work if the operator maintains them. I have flown 2 Lear 23's and the autopilots worked just fine. You have to remember that the FC110 autopilot is an advanced wingleveler. So don't expect too much out of it. One of the problems I am seeing right now is that FAA Inspectors are expecting to see fancy manuvers on the autopilot in early Lears. And the pilots and check airmen are having problems explaining to these inspectors that the inspector's expectations are way too high. And the 35/36 autopilot doesn't work all the time. The FC200 is an upgrade of the FC110. And I have flown 35s without a working autopilot. Now, they are earier to get fixed due to the recency of its electronics, but they do continue to break from time to time.
As for no time in a 24, the LR-Jet type covers the 23, 24, 25, 28, 29, 31, 35, 36 and 55. It is possible to get a type in the 31 with a 135 ride and do your first trip in a 23. These aircraft are in the same 'family' of aircraft, so the Inspector or Check Airman only has to do a differences oral to qualify the pilot in the aircraft. A situation like the one described above show a lack of management attention and care. I have been fortunate that all the operators I have worked for would not put a new Captain in that sort of situation. He would have flown a flight or two with an experienced Captain, then a few trips with a highly qualifed FO.
If the FO's qualifications were stated correctly, the Captain very likely was very overloaded and that may have contributed to the accident. There are sometime when you are single pilot even with a FO. And there can be time you may have been better off without him. Based on my pass experiences, it is my guess if this was the first time the FO had flown in the 24, he was behind the aircraft.
FO qualifications are basicly Commercial, Instrument, 2nd class medical and breathing(maybe). The insurance companies have much higher standards.