I see that you're from the UK, so send it for overhaul to @Bearing Man: eBike Motor Repairs & Servicing - Homepage
And the motor will be better than new ...
1. No. If you have for example 700Wh battery, 1 charging cycle counts when you put in whole 700Wh, not matter in how many charging sessions ...
2. multiple charges are not worse than one complete charge, I think they are even better as they put less stress on the battery
3. yes, it takes many...
This was the case only for Gen3, as at that (covid) time there was a huge bike and bike parts shortage, and they released top end spec models first as they need much less & more expensive bike parts to assemble them ... But now it's the opposite as they have apparently overstocked Gen3 models...
I think this was the case only on Gen1 Levo/Kenevo and early firmwares of Gen2, where you could increase top speed by altering the wheel circumference to much lower numbers ...
Basically for Gen3 Levo you need M3-500/700 battery, which is the same as M2-500/700 except different rockguard, so if you get M2-700 you also need to replace rockguard kit for Gen3 version ...
Again, you cannot really compare 90Nm vs 35Nm motor reliability wise ... If you restrict 90Nm motor to 35Nm you will also lower down the failures significantly ... And Mahle on SL is loud af ...
If you need to remove the drive side crank just use the bolt from the non-drive side ... this part of the bolt you are missing is for crank extraction purpose only ...