@Fermooto
A couple of your criticisms are legit while the others seem like you didn't even read the manga.
For starters some of the bad grammar and context is due to translations, but some is due to the fact some of the characters speak in role-playing-ish speak and some speak in "leet" speak. That is how it is written, these are supposed to be kids in a game after all. Myu is can be bad for it in the LN (this is based off of) for using stereotypical gaming phrases.
As for the " picked the wrong gender and doesn't re-roll" if you actually read the first Chapter (Page 22 to be exact) it states what happened. You can't choose gender/sex in game, it is based off of your sex/gender IRL. The game automatically detects this and detected Yun as a girl due to his feminine face and auto selected his sex as female. He did in fact try to re-roll, but was stopped by his older sister who black mailed him into staying as this character since it is technically impossible to play as the opposite sex. She threatens to expose his "dark history". Which is sort of explained later in the series.
As for his skills, they aren't trash technically, compared to everyone else who has EZ mode skills, Yun picks one of the harder ones at low levels. Bow's aren't useless per se, they just have a stigma around them due to an event that happened in the beta, mostly the fact that they require ammo which is a pain in the ass at low levels (this is skipped over in the manga which I agree it could be done better). Besides Yun isn't playing this game as a hardcore player like the others, Yun is playing as a crafter so having combat skills are irrelevant. Anyone who has played a hardcore MMO can tell you there are some classes and build that aren't meant for combat but are needed nevertheless.
Plus most of the characters in the game played the beta (Myu, Taku, and Sei all did) which Yun did not, so they already have a head start on him. Not to mention the manga is only at Volume 5 of the LN, there are still 11 more books of story that changes everything.