The quoted statements are rather arbitrary and although not entirely incorrect, they are not justified in the case of the Las Vegas shooter, Stephen Paddock. Also, for some unfathomable reason, Paddock's age is some magical negative factor, as to why he couldn't have done it. And that Paddock had no prior military experience, proves he couldn't have done it, is also some kind of fable.Even highly trained Navy Seals would have a difficult time running a full auto weapon for 10 minutes straight. Such weapon systems are brutal on the operator. They require tremendous strength, stamina and expert troubleshooting to keep running. Full-auto weapons overheat and jam. They demand incredible strength to keep aimed on target. They require expert reloading and weapons clearing in the case of jams, and the hotel room would have been so full of smoke and powder residue that it would be almost impossible to keep breathing from that enclosed space.
First off, I have to explain that Paddock did not have, or use, automatic weapons. They were semi-automatic rifles that were modified with a "bump" stock, allowing a rate of fire that was similar to that of automatic weapons. I would venture to guess, based on the audio recording of Paddock firing, that his rate of fire was somewhere around 300-400 rounds per minute. That's about half the rate of the average automatic weapon, such as the M16A2, or the M4A1. Still, that's a respectable rate of fire. A high enough rate that he killed 59 people and wounded many others. He fired for about 9-11 minutes. The news has it that 10 semi-automatic weapons were found in his room, with bump stocks. Assuming Paddock used banana magazines, of 40 rounds per, and while firing emptied a magazine every 30-45 seconds, then that would amount to 10 magazines expended in 560 seconds, including ten pauses of about 12 seconds each to change out between weapons and/or magazines. So 10 magazines in about 10 minutes. Four-hundred bullets peppering hundreds of people for ten minutes. Yes, I would say Paddock could easily have accomplished that. And without aiming, even.
I'm former military, so yes, I have some experience in these type of things, however, my former training does not automatically confer some fabulous skill that allows me to do a Rambo. But, then again, I'm not motivated to go out and shoot a bunch of people. One thing we were taught in the Army is that a highly motivated individual can perform at a greater rate than a person who is lacking the same level of motivation. So could Paddock have accomplished this killing spree by himself? Absolutely.
I'll have more to add later.