Ok I got everything working in acceptable manner, since some people are similar to my situation I want do an update on what I did.
1. Got homebrew access via brower hax, download the hax file to the root of the SD card, go to internet browser on N3DS, grabbed the image code and it ran just fine. (I never needed homebrew as I used cubic ninja with GW)
2. Downloaded menuhax to the SD card under /3ds (aka homebrew folder), install menuhax so I don't need to connect to internet every time I want to launch homebrew (this is basically the same as DS profile exploit for the GW except it can launch other things besides GW)
3. Downloaded Tinyformat to homebrew folder, ran it and unlinked my sysNAND and emuNAND. (Never needed this before either but apparently its good to have it unlinked, plus I can have different theme for sys vs emu so its easier to tell which system I am under)
4. Since N3ds reseted to factory default after unlinking had to make a new profile etc. Then ran brower hax -> menuhax again since apparently I need to install again due to unlink, tedious but not difficult.
5. Downloaded luma CFW lastest version to the SD card. Then in homebrew menu launch luma CFW, I ticked the option to show NAND info, I want to be 500% sure that I am in emuNAND before doing anything crazy.
6. Once I made sure I was in luma CFW emuNAND, I went to system -> update and pray to god it was updating emuNAND and not sysNAND, even though I was 500% sure it is.
7. System restarted, went back to homebrew, launched luma CFW again, everything works ... eshop access no problem, I installed MHG demo via BBM and it works, including online.
8. Finally I downloaded GW homebrew files as well, so I can enter GW emuNAND via homebrew menu (ds profile doesn't seem to be working anymore), now I have 2 emuNAND, luma with 11.0 firmware, and GW with 9.2 firmware, can choose either via homebrew menu.
Only downside with luma is the SD card in my GW card can not be read, so I have to place all games inside N3DS SD card as Cia. GW card still work in GW emuNAND of course. I STILL do not know if GW 3.71 on N3DS work with firmware 11.0, if anyone can confirm it would be nice. Don't want to risk restalling everything again so I am just gonna leave it and use luma for now.
The a9lh method looks risky as hell, since you actually need to downgrade sysNAND ... my number #1 policy is to never touch the sysNAND no matter what, so I am going to pass. The extra 20 second or so I may save is not worth bricking my N3DS even if its only 0.1% chance of doing so.