Hah been a while since my question, but I have since finished my battery and took it for a spin on my garbage diy 1500w bike.
The bike itself was able to reach ~60km/h full curry, and munched quite steep hills without a complaint.

The BMS from Em3ev.com works great if it weren't for my slightly bad cells. But it manages with balancing and so far, no issues. The battery also lasts a good couple hours on throttle only, but does suffer a little voltage sag.

If anything I should have stuck to 14s so a BMS and charger is easier to come across(even though em3ev modded mine to take 13S), and I feel that for this motor, that extra voltage would really help.

I've since disassembled my single speed bike and now converting an old dual sus mountain bike to mid drive. All those gears and possibly 80km/h is too juicy to pass up