Please have a look at the Cherry switch wiki here, it will hopefully clear some things up for you. You want to pay attention to the *peak* force before actuation, not just the actuation force.
http://geekhack.org/showwiki.php?title=Cherry+Corporation+Switch+WikiI like the Zibal 60, but aren't blacks noisy? I read somewhere that their click noise is even worse than the blues, and also that browns seem to be the most tactile between all.
Blacks are not noisy as far as MX switches go. Blacks use a heavier spring than blues and are linear (read: non-tactile), so I do not think they are what you are looking for here. Not counting uncommon switches like greens and clicky whites, the blue switch is the only standard Cherry MX switch that has the clicky sound at actuation. All of the switches will sound the same when bottoming out, although if you use a higher force switch (like clears) you can avoid bottoming out more easily. Using a board with PCB-mounted switches or adding o-rings to the switches will quiet the bottoming out sound a little.
In addition to this, there is one thing that I am confused about. The "UK Filco Majestouch-2, NKR, Tactile Action Keyboard" uses browns and requires 55g force to actuate whereas the Blackwidow with blues need 50. I thought the browns are more tactile and need less force?
Blues require approximately 5g more force to actuate than browns, which is just enough to be noticeable when typing. While the force *at* actuation for blues just needs to be about 50g, they must pass the peak force of about 60g to get to that point. See the force diagrams in the wiki.
And they are both the same 2.0mm!?
All Cherry MX switches have 4mm of travel and actuate at roughly 2mm.
I thought the browns are more tactile and need less force?
There is no Cherry MX switch that is both more tactile and lighter than blues. You are probably best off going with browns or reds. Browns are a little lighter than blues and are noticeably less tactile. Reds are even lighter, but are linear (non-tactile).