Re: Batman-"the most realistic" superhero?
I agree with the OP. Batman is by no means realistic. He is definitely more grounded in reality than other superheroes but that doesn't exactly make him realistic.
The argument people use to defend Batman happening in real life is absurd. They will say stuff like "Anyone can be Batman if they're rich and do a bit of training around the world!" Not only is that statement false but it shows that these people don't understand what Batman is and what he is capable of.
You know how people say that no one is perfect? That we all have something we are good at and something we are bad at? That doesn't apply to Batman. He can do everything. Both physically and mentally. Physically, he has the perfect body. If he was in the Olympics, he would win a gold metal in pretty much every single field. A person simply cannot train his/her body to complete perfection. Swimmers train their bodies their whole life so that they could have the perfect body for swimming. Runners train their bodies their whole life so that they could have the perfect body for running. Batman has the perfect body in each field period. No person will ever be able to achieve that and if there is someone who will, it will take them their entire life to do that while Bruce finished his training and was ready to be Batman at the age of 25 in the comics.
That is excluding all the martial arts and mental training Bruce had to go through. Batman knows 127 martial arts styles and has incredible detective, strategic, tactical, and scientific skills. These 3 things (perfect physical body, perfect and all martial arts, perfect mental training) each, IF possible to achieve in the real world by a person (which they're not), would take that person their entire lifetime to achieve that. Bruce achieved something that would take a person at least 3 whole lifetimes to achieve before the age of 40. Even the more realistic versions of Batman - the Frank Miller Year One Batman, Long Halloween Batman, and Chris Nolan Batman - despite being more grounded in reality are still not versions of Batman that can technically happen in the real world.
Everything I said so far excludes the first point the OP made, which is the technology behind Batman, which is not available in the real world at the moment.
The reason why many people believe Batman can happen in real life, even though he can't, is due to the psychology behind Batman. Bruce is so determined and motivated to reach physical and mental perfection that we, as the readers/viewers (depending on the medium), buy it that a man can become something as larger-than-life such as Batman. However, that is simply not the case. If you think about it, Batman is almost in the same league as Captain America in terms of physical abilities. It's just that Marvel is a more realistic universe than DC is and due to that, they couldn't have a man like Steve Rogers reach physical perfection with just physical training so they brought in science fiction and had him injected with the Super Soldier serum but since DC's universe is less grounded in reality so they didn't have to do that with Batman. But if Batman originally was created by Marvel and Cap was originally created by DC, Cap would've probably been the one that went through a hell of a training to reach the level he is at and Batman would've probably been the one injected with a serum that would make him reach the level he is at.
As for for how relatable he is, Batman is one of the least relatable characters in the DC universe. Guys like Superman and Flash may have incredible powers but at the end of the day, they are Clark Kent and Barry Allen, two ordinary citizens living in Metropolis and Central City respectively that struggle with women, taxes, jobs, etc. while Bruce Wayne is a rich man unstable (to a degree) and completely obsessed with eradicating crime completely and is not afraid to push people away or to give his life away in order to achieve that.