New to D3 but play HardCore mode    (and you also have EU battletag). To know details, Google is your best fren. but in short:

1) greater rift (GR) is accessible using GR keystone fragment (dropped by Rift Guardian) in Nephalem Rift event. You will get Trial Keystone first (100% drop chance in Torment VI rift). Trial keystone will open trial GR. Trial rift will decide GR rank.
2) you can create Infernal Machine (IM) from 4 different keys and you need blacksmith plan called "infernal Machine plan" dropped by any of keywarden (drop only once, if you already teach BS)
3) fastest way is to do adventure mode, when u can travel anywhere

Live D3 RoS gameplay is here: D3RoS

HC eh?

Awareness (Passive) is your best friend

Welcome to Diablo3...

Feel free to add me... I main a DH and play in Hardcore too...

My Battletag is CrankyMonky#2942

Here is my HC DH for you to have a look... My current DH can solo up to T4 (T5 doable but scary)

http://us.battle.net/d3/en/profile/CrankyM...2/hero/32908110

played since launch... Really feel like not enough char slots lol

Anyways... Quick advice... If the bow that u have equipped now is the best bow u got.. Try to enchant it at myriam for a socket... having socketed an emerald will really boost your DPS...

See you tonite if u login ... We can do some T1 runs

Socket also is one of "primary" properties u can select from the option. or use DICE to add socket to weapon.

read dice description bro, "will add soket to unsoketed weapon".. this is main use of the dice so u no need to destroy useful primary prop to have socket on weapon..