Performance wise you should see an increase of up to 15% with most applications. The M2 runs hotter than the M1, so for sustained load tasks, it may end up being a bit slower. However for the reasons you bought this machine it is still worth the upgrade. You get MagSafe and a bigger, better screen, better speakers and nicer design plus an increase in performance for day to day things. Depening on your use case the loss of the touchbar may also be a positive. If I’m guessing right your work will involve a lot of opening and closing of documents and the M2 Air will be able to handle it perfectly fine I think.

Depends a bit on what model year it is. If it is a “Retina” machine, you won’t be able to upgrade the components in the machine except for the drive with some adapters. If you have a machine from 2012 or before which ich chunkier and has a DVD drive, you will be able to change the memory (RAM) and the hard disk. Software wise the machine is no longer supported by the newest OS, but with so called patchers you can run modern macOS versions on your laptop, as the other comment mentioned.

I hope you get a lot of enjoyment out of the laptop! Don’t mind the iditos that comment “didn’t read” instead of scrolling on. In any case, I see a lot of people using Anki. The YT channel here! learns japanese and also went through a Mac transition, so I hope you can find some useful tips there. Regarding the Diary App, with the next iOS version (17.2) Apple will release the Journal App, which should do something similar to what you are looking for. It hasn’t been confirmed yet but it may also be available on Mac. Day One is another one that a lot of people use, which is also available on Mac. Other than that there is also Obsidian and LogSeq, which can be used as a diary. They use normal files so could be encrypted while you’re not using them.

If it is an SSD and you are sure of that, it won’t be a problem. SSDs store informatin without having to have power applied and in the form of tiny physical changes of the storage which can only change with electricity and is not affected by magnetism. TLDR, it will be fine, especially if the SSD has a metal enclosure.

I would recommend to look for a refurbished M2 or M1 Air with 16GB of RAM. The model you have, while slow should still sell for some good cash, so you could offset the cost of the new device with your old one. If you’re looking for M1 specifically, I don’t think they will fall much further in price between the sales on now and summer next year. Technically Apple still sells them, so they count as current models.

I can only speak from experience regarding my M1 Air, which has had the whole cracked screen thing when it came out. I have brought it with me to uni and a bunch of other places with and without a sleve and it was fine. If you avoid dropping your backpack (even from low height) and also make sure nothing is putting pressure on the display lid, eveything should be fine. I also have seen people by hardshell cases, which will take some of the pressure of the shell, so that might be worth looking into.

My first guess is always overheating. If the machine is not too dusty, it could be the battery. If it shuts off whenever you do something demanding/ open an app for example, it would indicate a battery issue. If the fans are louder than usual/ when you firt got it, it could be overheating.