For premix use as stated in manual, usually 2% or 1:50. More oil is not more safety. More oil means leaner air/fuel mixture which is less safety, so you have to increase jets. Not worth the fuss unless you are riding full on mx tracks. Any synthetic oil designed for trail will do, meaning it has low flash point. If it dyes fuel in certain colour, generally blue, green or red even better so you know you have a premix.
Gearbox general use ATF is ok, but it becomes grabby when fine dosing the clutch in tough terrain. Better choice is any engine or gear oil 10W 40, with JASO MA2 standard. It can be gearbox specific oil or general 4 stroke oil.
MA2 is wet clutch approved. Avoid synthetics. Semisynt or even mineral is far better. But mineral is hard to find nowadays. Replace 10-15hrs, depending on use.
Exact oils are what are available to you locally. Pricier does not mean better.