80:1 with synthetic oil is just fine in a trials bike. May not be great for motorcross, but this is trials and not motorcross. If you ride a trials bike like a motorcross bike, well you got the wrong bike but that should run a motorcross type oil mix. My old '96 Fantic was running 80~90:1 mix and it still has a tight top end with tons of compression. 15 year old bike never had a top end done, EVER. Anyone saying you will need a top end in a trials bike in 6-months at 80:1 does not know trials.
As for oil, any quality synthetic. You just spent how much on the bike? A quart/litre of good synthetic is $10 and will last a long time. So long I forget the last time I bought it.
As for fuel, these are performance engines. They run a good deal of compression for that strong torque. The port timing will keep the cylinder pressures up. They need octane. Premium pump gas could work, I have never used it. Ethanol, it slightly leans out the fuel mix. The basic 10% should not really be a problem. Unless you are a pro you will never notice that it is slightly off. The problem is material compatibility. The materials in the fuel system are not intended for Ethanol blends. Short term it will all appear fine, long term it is more likely you will have wierd fuel system issues. For as little gas as these machines use I find sources of good gas. Also helps in fuel storage, non-ethonal fuels tend to be more stable when stored. I have used 2-year old AV gas that was stored outdoors (not in the bike) and it was still good, not varnished, bad smelling, etc. Half of the fuel had evaporated in that time, but what was still left burned fine. Personally I have access to 3 easy sources of race gas and at least one easy airport to get gas from. The Phoenix area pump gas goes bad so quick I can't store it for more then about a month before it starts turning into wierd jelly.