enough stake to bury your account more than 4 meters underground

Yes they can and some accounts, the spammers and the plagiarizers need to be buried, but the people with that power are being pretty careful and respectful of peoples reputation. They still have their reputation when it comes to being de-rewarded due to the type of content they post.

As for the language barrier, I believe there are people working on the ability for people to pick the language they want post displayed in, so if you only know one language, like myself, all the different languages will be auto converted to English. I do not know how far a long they are on it, but when it happens people in Nigeria, Spain, France, Russia, will be able to select their home language to read, write and post in. It may be a few years down the road or just around the corner, but I believe they will be able to do it.