I agree with you here, plenty of people just make the talent build and that's it. For most if not all heroes in the game, 1 talent build isn't gonna be the most successful every game you play, it's all situational. It actually might motivate myself to start making guides for Assassins, being they are what I primarily play.

Hatred stacks still appear above your hero portrait in the bottom left corner, also if you get the 16 talent Tempered by Discipline, those stacks will show up as well after your 10 stacks of hatred. What Terando said is correct, they removed practically all debuffs from displaying for some reason. Maybe to add a bit of difficulty to the game or something, but I personally like seeing debuffs on my hero. Hope this helped!

I play on a 28" UHD monitor, the ingame cursor is so small, I lose my cursor multiple times in a team fight because there's so much happening. Blizzard should consider pointer options ingame, for size or even maybe different types. More input on this would be awesome!

It will definitely get more popular in due time. It finally fully released a few days ago, and the pro scene is right around the corner. BlizzCon NA Tourney is just a week away and more to come, it's going to be exciting. I believe it's much more entertaining to watch than LoL as well, in HoTS it's not just one person carrying a team like an ADC in LoL can do. You all scale together, level together, and overall the gameplay is easier (in my opinion). I pretty much stopped playing LoL...