Stay away from the .44 magnum "Dirty Harry" gun for your first gun. Once you're an experienced shooter, you may want to pick up a .44 but it's not a good choice for somebody who is just getting into the hobby. The recoil can be unpleasant (or downright nasty), and the ammo is ridiculously expensive if you don't reload your own ammo. You won't need that much power anyway unless you're dealing with the bigger bears
This entirely depends on the person. Some people like kick. My first handgun was a .41 magnum and it didn't beat me up, and it's quite fun. .44 mags aren't bad, it's not the wrist breaker forehead smacker that some believe. Same with a .50AE Desert Eagle. It's not a gun that kicks your ass, the people on youtube who get owned by one are worthless. Hell, even a 500S&W and the .460 isn't bad. Once again, I think they're pretty fun.
And a .44 is a light for bear IMO when it comes to me living or getting my ass ate by a large mean critter, .44s can make good range guns.
That short rear stock is a complete waste. If you do get one of these, you should consider replacing it; otherwise you will soon discover what getting hit in the face during recoil feels like.
.45 Colt kick isn't a forehead smacker. Most loads are toned down cowboy loads because everyone is worried about making a high powered round and sticking it in an older Colt and blowing their hand up. Also, replace the stock with what? A regular stock? That would require paying a tax stamp and registering it as an SBR.
Pistol grip only shotguns are not fun to shoot for any extended amount of time and aiming with them can be problematic if you like your teeth . The old saying " you don't have to aim with a shotgun " is far from the truth
Problematic if you like your teeth? Really? I've shot skeet with a Serbu Super Shorty before, just playing around, and the kick was like a 44 mag load.
Once again, not bad. But that is the truth, you have to aim with shotguns.
Anyway, for a first gun, I think a Mare's leg would be a terrible choice, but hey, it's your choice, do what makes you happy. When you get into handguns, just get something that fits your needs and wants. Also, don't worry about kick and power of a round. First round or two you just shoot it, learn how the gun feels in your hand during recoil, after that, you can aim and you'll be good.
Since this turned into a mini rant, for the record, it's .45 Colt, "long" was never part of the name, just something that makes my skin crawl.