1) I'm not going to judge the guy based on a film I didn't see, that film being Fast and Furious. It's not the same dude as the first film, which was actually pretty enjoyable, but from my understanding Fast and Furious was along the same lines. I don't know if the guy is a good director, and even if he did well with Fast and Furious I have no clue if he'd do well with a film like this. They are relatively different. Still, it's too early to pass judgment, especially when his credits primarily include obscure stuff.
2) The writers are good. Iron Man was a witty film with a lot of character development, which is primarily what the original Highlander was. Still, just because one was good doesn't mean the other will be as well.
3) Even if Highlander is awesome, it's dated and cheesy. The sequels are all terrible. I love it as much as the next man, but if I was involved in film business even I would want to reboot the franchise in hopes of fulfilling its true potential. The only reason to remake something isn't always due to lack of imagination. In the case of Charlie and the Chocolate Factory, it was to correct what was essentially an abomination by bringing it closer to the book it was based on (ironically enough, everyone knows the film so they hated the more accurate remake).
I will not pass judgment. I'd rather different names be attached to the project, but until I know for a fact they are going to fuck it up then I won't be negative. To react otherwise is, honestly, pretty childish.
Though there will be no replacement for Sean Connery.