1) First

2) for 1080p gaming, even a 1060 can get you max settings, if you have a plan of upgrading your monitor to 1440p/4k resolution, just get a 1070/1080

3) i7-6700k is sufficient for gaming as 4 cores is enough for games nowadays. Except you will utilize that extra 2 cores from i7-6800k in the future

by opt for my opinion, you can even get a SSD with bigger capacity and save some more cash 

i7 6800K requires mild overclocking to match the single core performance of i7 6700K thanks to the higher stock clock speed of 6700K, if the apps/games you use is heavy on single core (or single threaded) then 6700K will pull ahead of 6800K in stock speed, 6800K will edge out only when multithreaded operation/process is involved.

If you plan to play games on 1080p resolution only then don't spend too much on GPU, there are various videos showing resolution bottleneck symptoms (1080p) on high end Pascal card on YouTube (like Digital Foundry), you are strongly recommended to DSR to push more graphics details and better image render in games when going for GTX1070/GTX1080 (or higher).

If you don't plan to overclock at all, then i7 6700 is enough (can save up to RM 1000 since no need to get expensive Z170 + decent 3rd party CPU cooler + performance RAM).

As for GPU, GTX1060/GTX1070 is enough for 1080p for now, the highest end cards (like GTX1080/Titan X Pascal) in the market are still not fully qualified as 4K UHD card (too much compromise), wait for next gen card instead for 4K UHD gaming.

No, next gen Intel Core i7 Extreme Series CPU (Skylake-X and Kaby Lake-X) will use LGA2066 socket, so Broadwell-E will be the last supported CPU on this socket.

LGA1151 is the mainstream CPU socket (for normal consumer), it supports Skylake (current 6th gen) and the upcoming Kaby Lake CPU (7th gen), performance gain between each generation is very low (at least for Intel CPU) so you don't really need to upgrade year by year unless you are too rich to donate the money to Intel 

Picking LGA2011-3 socket won't be a waste, you get what you pay for, it is still a beastly CPU platform with supreme overclocking ability, the performance gain per generation is too small to convince me for an upgrade from the previous generation.

The only noticeable difference is just the clock speed (couldn't find anything apart from this), Asus is really an expert in how to overcharge their customers 

Sounds like a good plan to me 

But SLI (and CF/multi GPU config) has a lot of issues currently, it doesn't always guarantee good scaling 

This will definitely do. But the Windforce card has no backplate which is a let down. I would suggest Zotac GTX 1070 Amp Edition with better aesthetics, a little faster core clock and share very similar price.
Photoshop/Illustrator? 6700K is more than enough actually haha. Not really necessary to go for 6800K and above unless you perform workload intensive tasks such as rendering, video encoding, superb multitasking (play GTA V while doing video editing and encoding simultaneously).

I'll suggest on getting 6700K, then choose the GPU you preferred the most (I heard the Gigabyte Xtreme Gaming performs very well, at least it's cheaper than Asus Strix). Save the cost and use the leftovers to upgrade other components or use it as a kickstart for future 4K monitor.

No idea about 4K monitor because I have never used it before haha. Try asking at the monitor discussion section and ask for advices from the professionals there.

Extra info, if you can wait until Q1 2017, you might want to try out the newest RYZEN CPU by AMD 

Sounds like a good plan to me 

950 Pro is a NVMe PCIe SSD while 850 is just a normal AHCI SATA 3 SSD, the speed difference is quite significant, same goes to the price tag 

But SATA based SSD is already fast enough for normal users to feel its speed advantage over the traditional HDD, 950 Pro is more like a luxurious car, I wouldn't recommend anyone to get it now unless you transfer a lot of stuffs in between all the drives that you have in your rig due to its price tag, wait for few more years until the price gets settled down

512GB is faster than 256GB (both read and write).

Yes just stick with SATA based SSD (like 850 EVO) will do unless you have extra budget floating around and don't be fooled by "M.2 SSD" term, there is also M.2 SSD using legacy SATA like Samsung 850 EVO M.2 and its price is almost similar to the normal 2.5" SSD (speed also same, just form factor is different).

Speed wise is almost identical as they are using SATA 3 and is being limited by the speed of SATA 3, unless clearance is an issue, I don't see any reason to pick the M.2 over the 2.5".

If you transfer data between two 950 Pro then you will benefit from the speedy I/O specs (provided you aren't being bottlenecked by other I/O like RAM and system cache size), if you transfer from (or to) 950 Pro to 850 Evo (example), then you will experience slightly faster transfer speed in the first few seconds (thanks to system cache), then eventually it will drop to SATA 3 speed as the 850 Evo couldn't catch up the speed of 950 Pro and 950 Pro will have to wait for the data to finish copy to 850 Evo first before continue.

And for the performance in games, well it depends on the file block design of the game files, if they are broken into small pieces then the one with higher sequential 4K read will win the competition, and no doubt 950 Pro will win it in this comparison, same goes to all the other categories, but the problem is "is it worth the extra money for a shorter loading time (for like few seconds only?)?" 

They will be unveiled this week in CES 2017 (mostly 5th of Jan).

I will wait if I am not in a hurry since the price is almost identical.

actually some of the shop already got stock in hand just that they don't want to start selling.

you may approach them to check.

NDA
pls tahan more another 2 days la

What is your PC spec and power supply? Also, make sure your display cable is connected to the graphic card.
Entirely up to you. Depends on shop too.

Yes, i7-7700K is enough.
Depends on your monitor. 144hz doesn't come cheap. Also, to get 144 FPS+ is not easy with GTX670 for games these days.