Can we assume that Snoke is basically Darth Sidious reincarnated?
Like others above have said, the popular theory is that Snoke is Darth Plageuis.
Is Ray really Luke's daughter and if so does he have more than one child?
We can't say for sure yet.. I prefer the theory that she was one of the disciples in Luke's new order before Kylo and the Knights of Ren wrecked everything.
Why is Kylo Ren or rather Ben Solo such a lame **** when they potrayed him as a badass Sith before the release?
... a lot of people have been complaining about Kylo/Ben as a villain. I'm not sure why.
The point of his character is to be living in Vader's Shadow; Vader can be seen as an unattainable goal for him. However, if you really, really dig deeper, we can begin to see how much Ben is dedicated to the cause, despite his inner conflict.
He killed his father to try and deepen his own connection to the dark side. Sure, he had remorse and regret in the -beautifully shot- scene prior, but he was cold and callous afterwards, signaling a drastic shift in his character. Even Vader/Anakin couldn't bring himself to kill Luke and tried to turn him to the Dark Side. Luke obviously won... but when Han tried to redeem his son, he met his end. It's almost like the complete opposite happened.
In terms of physical feats and endurance, Kylo took a full Chewie bowcaster blast TO HIS STOMACH. If you recall, this same bowcaster instantly killed ARMORED stormtroopers. Despite this crippling injury, he was still capable of handily beating Finn, a trained stormtrooper. Even his injuries sustained by Finn and Rey's hand were unable to knock him out completely.
Compare this to Obi-Wan in the prequels. He was out of commission after two precise lightsaber strikes from Dooku in
Clones, and
Sith repeated this with a simple push by the same character. I'm not saying Obi-Wan is weak, but Kylo is underestimated, in my opinion.
He stopped a
freakin' blaster shot from Poe at the beginning.
Why exactly did Luke leave the republic instead of wiping the floor with Bens face and destroying the first order?
You want the personification of all that is good in Star Wars (Luke) to kill his own nephew? Not very characteristic of him. Again, as others have said, he felt guilty, and perhaps he wanted the Jedi legacy to die with him so that people like Ben would not arise from his mistakes.