Try this. Works on my ipad. In LR Mobile, choose your image, then Save To Files. A little fly out will open with your choices of where. Default is Adobe cloud, and on mine, Apple Icloud. On mine, there is a circle with little dots at the top right of the fly out that lets you add other choices to your options besides Adobe cloud. Google Drive and perhaps others should be there, but it may not be turned on. Turn it on and it should show as an option you could choose.

I had something similar happen to me. I never understood how it happened but at some point my raw files (ORFs) began being re-labeled as Topaz files on my mac desktop, even though Topaz programs had never been used on them. I will tell you how I think I fixed it. I selected one of the photos that had gone rogue and had a Topaz icon, clicked Get Info, and where it says Open With, I deselected the Topaz program and selected Lightroom. Then I checked Change All. Miraculously the icons changed back to ORFs and I could open them again and the programs that had refused to work began to work properly. I have NO idea whether something similar will work for you.

I have read that this type behavior was associated with the Catalina OS, especially the beta version. If you Google this you will find technical articles that offer solutions where you have to go into the command line interface and that terrifies me so I was glad my problem was so easily resolved.

And I suggest that you post this problem on the Apple Discussion board before you get too deep in the weeds. I have always gotten good help from them.

Looking at your workflow I don't see that you mentioned having a backup system. If you don't, I'd strongly advise you set one up, so that your photo disk is not the only place your photos are stored. Time Machine is great for this and it's already on your system. A backup might or might not have saved you from this gremlin but we all need one anyway.

I have done this before with a small group who met on one of the sub forums. We rented a house on the Maine coast and spent a week photographing cool stuff we don't normally see and having informal teaching sessions where we presented things we were especially good at or interested in for the group, sharing our photos, etc. We shared cooking duties and grocery costs so it was very inexpensive.

Time Machine which came on your iMac does a perfectly good job of backing up your photos. I keep my original photos on external drives backed up via Time Machine to a different external drive. It is automatic and invisible in the background but it's there. I have had to use it once when one of my photo external drives failed, and I used Time Machine to restore those photos to a new external. Smooth and easy process.

I do use Backblaze for a second/cloud backup as well.

Endless. There is no better photographic venue for a person with limitations. Lake Louise and Moraine Lake are easily accessible, with short flat walks from adjacent parking areas. Icefields Parkway is like one long tripod set-up location. You can make wonderful photos right from the road. Some especially beautiful areas - like Peyto Lake and Sunwapta Falls - are short walks from parking lots. Bow Valley Parkway has opportunities to photograph animals right next to the road - bears, eagles, elk, osprey, wolves, etc. If you make it a bit past Jasper, there's a nice boat ride on Maligne lake that takes you past and to some very scenic spots.

I am not sure they are still in print but Darwin Wigget's photography guides to Banff and Icefields Parkway were very helpful to me the first time I visited.

DPRevived.com is functional and has enrolled over 900 refugees from DPR in less than 2 days. There is significant tech expertise among the founders so while they have glitches as any new forum built overnight might expect, they are solving them and moving forward at the same time. They are informing the citizenry about what they are doing and getting feedback as they go. At this point the build just involves the forums but they have plans to make it more. Watching a forum be born is pretty interesting. A certain amount of chaos, a lot of creativity.

DPRevived is an effort to keep the forum division (not the reviews) of DPR going, giving forum members an opportunity to re-convene in a familiar format. It's a home-grown project by some tech savvy members to salvage the community created over the years. It opened last night for those of us wanting to test it out. It's got a bunch of bugs as one would expect for a one day old forum created in such a hurry but it has promise.

I use Time Machine for my local backup (my computer and my two external photo drives) on a separate external drive. It runs quietly in the background. I use Backblaze for my remote backup. It too runs quietly in the background once you get your initial backup completed (mine took a few weeks, as I have about 100K photos on the externals).

I have blessedly suffered only one disk failure, on one of the external photo drives, and was able to restore it to a new replacement drive quickly and easily using Time Machine.

Photoshop is a pixel level editor so you should probably not work on your original in PS. You will want to find a workflow that is easy for you to follow and preserves your originals. Here's mine:

I import all my photos into Lightroom, and do my main editing there. For those I want to work on in Photoshop I choose the Edit In /Photoshop command in LR, and chose Edit A Copy. This leaves my original (raw) file in LR unaltered. Once my Photoshop work is done, I save it as a PSD file back into LR so that it sits down right beside the original, making it easy to find and easy to tell apart from the original.

Time Machine is already on your MBP. I use TM to back up my hard drive and my 2 externals. TM has saved me much grief when I had an external full of photos go bad and could not be mounted or read. I restored its contents to a fresh external with TM quickly and with absolute ease.

The charger was external. No Oly mirrorless that I'm aware of have ever been equipped to charge a battery that's inside the camera. It was (at least not noticeably) swollen when it was put into the camera, but it was obviously swollen when I pried it out.

My experience with a pair of Wasabi batteries was with an OMD EM5 some years ago so it may not be relevant to your current experience, but I consistently got about half the number of shots as I did with the Oly battery with the same shooting conditions and settings. My adventure with off brand batteries ended when one of them swelled up inside the camera while I was on a trip and I had a heck of time prying it out with a metal nail file. At that point I abandoned my quest for cheaper batteries.

I failed to mention one thing I was worried about : old peripherals and a new Mac Studio. I was pleasantly surprised that they all worked - the 15 year old monitor, the 2 photo drives and the backup drive, the 2 printers, the Wacom tablet. It might be a concern to you switching from Windows with any external equipment you want to use as to mac drivers, cords and connectors, etc. I did have to buy one adapter to connect the ancient monitor to the Studio.

Lightroom/Photoshop will look and run the same on a Mac or a Windows machine, provided you are using a new version of LR/PS. Very old copies of LR may not run on new machines with up to date OS. Machines from the two systems feel somewhat different to the user. Switching from one to the other for the first time can be frustrating but it doesn't take long to adjust. Most users will have a preference for one over the other even after becoming competent with both. I have used both, but I have a strong preference for the Mac machines for a number of reasons that may or may not matter to other users.

I see people mention the non-upgrade-ability of Mac's as a barrier and I confess that when Apple starting sautering them up where I could not get inside them to switch out simple things like ram modules and drives, I was very annoyed but not annoyed enough to switch because various features of Windows machines annoyed me more. At that point I started buying with future-proofing in mind and instead of getting the entry level model, I got one with more specs than I thought I needed at the time, but that let me get 12 years out of my last Mac mini, and I'm hoping my new Mac Studio with do the same. It should outlive me.

Having briefly tried and discarded several popular brands/styles, I've now used a DSPTCH sling strap for over a decade. I like that it connects to the side lugs, leaves the tripod mount open, keeps the camera right side up and by my side.