ok, first of all, I got to ask, what is the menu of the neo mk5?
It is well... I dont know how to explain or answer that because I don't have one yet and I only have used it a few times. But it is like by the users and my friend that owns one a lot and I find it easy to use.
could I choose, if I want 3d or 2d icons?
As of now, no you can not but maybe you will be able to in a future release.
Will it have always good updates?
Well I don't know, but it seams like you might get them but they will not be the fastest ones ever.
second, does it play EVERY game? even the new ones? Like lunar knights, and others?
Yes I have not yet found a game that does not work on a MK5.
another thing that I didn't understand is the compatibility of the homebrews, some places say 100%, other 75% and other says that is not very good because don't have DLDI support, so, its good or no after all?
Almost all homebrew I have tried worked, I just couldn't get snesds to work and after I get a MK5 I will try things to get it to work more and if it doesn't I will ask for help. And if you want to know more about DLDI read
this.I saw in some place, that it freezes sometimes , is that truth?
No, the Neo2/3 did have this problem but the MK5 does not.
it says, this could be used like passme for many slot2 cards, I am thinking about buy a g6 one, does it support g6? (g6 for gba games, at my country I think that is the best option).
Yes, I have tested it on a g6 and it does work perfectly but you would not need it as a passme device for playing gba games, and just wait soon there will be a way to get gba games to work on your nds. I had started working on a homebrew that would convert a .gba file to a .nds game but actually just couldn't take the time to code that much. I have a life and I just don't understand how coders do. Not to be mean or offensive but it is a lot of work and your time.
C'mon, i really needs answers, because the only place I could find it on my country (brazil), this is VERY expensive, even more expensive than the nds. (R$599,00)
here is a place that you can buy one that is a lot less and is only $59 USD which is a lot less and you get free world wide shippingAnd as far as I can tell 59 US Dollar = 124.292 Brazilian Real so that is not even close to how much you were going to pay.