What about the newer RX580 with dual memory? I have 2 of these with Samsung and Hynix(secondary). Currently mining at around 860-870 (after a great number of tests with different mem timings, OC/DC and miners) with 1200/2200.

There's no such thing as "newer RX580 with dual memory". Each card only comes with memory chips of a single particular brand. For the most 580/8 these days it's either Hynix or Samsung (heard of cards with Micron, but never saw them myself). The manufacturers are just too lazy to bother with writing separate BIOSes for each memory type, so they make one BIOS with straps for 2 or more memory types in it. If the card has Hynix chips installed, it'll use the straps from the Hynix table, if it has Samsung chips — then it'll use the straps from the Samsung table etc. So when you edit your BIOS, you just edit the straps corresponding to the memory type installed on your particular card. Judging by your clocks and hashrates, you've got Hynix chips on your card.

Is it safe to use the "my.electroneum.com" online wallet as a mining wallet? Will the coins make it there?

Try other pools, but if you'll keep getting this same error then it should be obvious what the problem is. 

Hello ,
Im actually mining with at 27kh/s on nanopool but it's seems that I get incorrect earning , Im supposed to earn between 2500 ETNDAY using current difficulty and 1800 ETNDAY using 24h difficulty average. But Im around 1200 PERDAY. Im sure its not about luck because nanopool ETN got 70Mh/90Mh of the network hashrate. Is it a scam or a bug ? How can I solo mine electroneum ?

New ETN Mobile App
https://play.google.com/store/apps/details?id=com.electroneum.mobile

You can use my referral code as a thanks for this guide
Download and login to the app. Go to More -> Earn Free Coins and Scan this QR code or you can just put the code 36AA87
You can win ETN by using it.
Thanks.

What kind of a 6-gpu rig produces only 700-1400 H/s? That doesn't sound right.

I'm not saying that sounds right... I agree, it does not.  I'm only reading what I see at Hashparty.io after looking at their stats for me.  When I look at the GPU Rig itself, I see: 

XMR: GPU0 381 H/s, GPU1 384 H/s, GPU2 385 H/s, GPU3 381 H/s, GPU4 376 H/s, GPU5 385 H/s

So - that would be more like 2,292 H/s

It's not like that for Ethereum, it is WAY higher.  This is just how it runs against XMR, I'm guessing.  For Ethereum each one is nearing 600 as I recall.

It is a 6-Rig, RX580