To be honest with you, I personally was not happy with some of the changes. However, its down to some small adjustments to timing.
This is just my opinion and how I dealt with it.
1) Indeed HMB initial 3secs of iframe is shortened but it refreshes 5x per resist. So still a total of 15secs iframe. Can just time using HMB a bit slower in some boss rotations to still have the same effect as before patch.
2) For pve, you dont really want to spec the Fatal Blade talent (bottom left talent). I believe its more for 1v1 and finisher kind of move....but I usually spec the middle bottom to enhance Q/E/SS for pvp.
And spec Crimson Blade for pve, that way you won't accidentally Flash Step on TT stage 1 ^^ .
You want to add One Strike, Ten Cuts into your rotation after 1-2secs of a Tab, since Hong bracelet will give massive dmg bonus to One Strike, Ten Cuts. And it also resets Tab. So I usually use it when I know I don't have anything else to reset my Tab.
3) Hypersonic talent is for pvp, since its range is 1x16m it can help stun, into a daze, into a air combo. But I find it hard to use still...so I usually spec the middle for more CCs when pvping.
And if you have the Ancestral Soul Badge, Sundering Sword is one of your main skills that reduce your Tab. I usually use it along with Lightning Draw to cancel animation. e.g Z>4>Tab.
4) No idea xD It was kinda cool to have a restraint skill.
5) Indeed, this is one of my most annoying changes ahah...in raids, I feel like I have to find a good timing to 1>RMB for Warcry. Just to make sure I keep aggro. Should have kept it on the same skills. But I'm sure there was a reason...??
Like I said, this is my opinion and how I'm dealing with the changes...hope it helps you to understand the new changes.
If I'm wrong, I apologize ^^