Seion
Ugh... Once again, Shadow clone jutsu requires kage/elite jonin level reserves just to summon a few, and even then it isn't worth using them to fight due to how much chakra they would use. Not to mention, it is a konoha specific forbidden jutsu, so how would they have gotten it without ever having went to konoha and somehow getting the hokages permission? Also, the uzumaki bloodline only increases their life force and longevity, not their chakra pools. Even if it did, with such a diluted bloodline, they wouldn't get much of a boost in the first place. If they were normal ninja that can use the shadow clone jutsu, then they are practically near kage level to begin with. Either way, that's enough of the plot hole inconsistencies. Ty for the chapter!~
It's been ages since I've cared to check the Naruto wiki, so I'll just answer the parts that I still remember. In regards to the elemental variants, I know there is a clone technique for most, if not all elements. They require a bit more chakra and chakra control compared to the basic clone jutsu. I don't think I mentioned them in my old comment though. Now for the part that I'm pretty certain you are wrong about; kids used basic clone jutsu to graduate. The standard graduation clone technique is an E-rank jutsu, unlike Naruto's B-rank Shadow clone jutsu. If I remember correctly, the three jutsu required to graduate (besides the other exams) were the transformation, substitution and clone jutsu. I'm pretty sure I was exaggerating the requirements for shadow clones a bit at the time due to my annoyance with the general troupe of shadow clones being used by basic genins. But, even special jounins rarely chose to use normal shadow clones, because they weren't easy to use, and carried risk. I'm also fairly certain that Hiruzen directly mentioned that he doesn't fight using shadow clones because of how little chakra would be split between all of the clones. [I am definitely paraphrasing since it's been years since I saw the episode, but I do recall him mentioning that it wasn't worth using the technique after 2-3 clones. I am up for being proven wrong on the exact statement though, since I never cared much to finish Naruto and could be misremembering.]
CkLance:Theres variations of the jutsu. Basic 'Shadow Clone' which only transfer information when dispelled. The forbidden 'Multi Shadow Clone' jutsu which transfers information, pain, & fatigue when dispelled. There are also 'Elemental Clones' with various effects. Shadow Clone has never been considered 'Kage level'. Preteens literally have to perform it for graduation from the academy.
Also Uzumaki's love peace but that doesn't mean they won't fight to protect themselves and their loved ones, their just more likely to seek a peaceful path to solving conflict. Also their clan's specialization is Fuinjutsu that doesn't mean they can't or don't use Ninjutsu, just that they prefer to use Fuinjutsu instead.
Actually the description of the jutsu is that it splits the chakra of the user equally among both the user and the clones, if you lack large reserves than learning it becomes a problem, but if skilled enough you could theoretically make thousands of clones but they wouldn't last long and wouldn't be able to use jutsu. The main reason it is dangerous is because most people unevenly split their chakra and suffer chakra exhaustion from suddenly losing too much, which can lead to exhaustion, heart attacks, and passing unconscious, which can result in you being killed in the line of duty. Naruto was said to have low/mid jonin levels of chakra reserves but he could make over a hundred because his Uzumaki vitality could deal with the backlash.