Yes, It will leak oil. How much will depend where the hole is. When the engine is running the oil is a pressurised system so it won't be supplying enough oil the the moving parts of the engine.
Take a photo with your phone and there is a button on the bottom of the comment box. Use that to add photos.
As a general rule If the cylinder head has ANY damage like holes and cracks Replace it. A cylinder head is cheaper than a replacement engine or a bike.
No, use whatever they recommend. Using wrong lubricants can ruin engines. As I said last night, this is not a well know motorcycle. It is a Honda 90 clone.
That is about right for a 110cc step-through scooter. They are very unaerodynamic. For a small engine it also depends on your weight and how much of a sail (wind resistance) you present to the oncoming air.
https://www.google.com/search?q=vuka+xl110+specs
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This is a short, it could be the wire from the fuse chafing on the frame, follow it thru to the wiring loom, failing that then look at all te wiring for a split or exposed wire.
I take help from online websites that have this service like helping in repair some like reliable-store have instant help.. others are a bit slow which I don't prefer... rest is up to u.. U can also get free manual works fine .