Re: 2% trading strategy, can this be applied for crypto trading?
the 2% rule means you don't risk more than 2% of your account on any one trade. if you have $100k, you don't risk more than $2k at a time. it's definitely applicable to crypto. it's a basic risk management strategy that hedges against variance.
even if your trading system is profitable, you could have a run of bad trades. if you trade 20% of your account at a time, you could blow up your account and lose your shirt after only a handful of trades. the 2% rule allows you to survive an unlucky run, and live to trade another day.
How can it work when earning only 2%? how about fees? or in 2% you already clear up all fees involve in trading and it's 2% gross earning/loss per trading
the opposite approach is the "all in on every trade" method that's so popular with crypto traders. 
I'm sometimes guilty on this with some altcoins. I just set limit, all in and boom. goodbye. next altcoins to trade please.
Should be 2% with all the fees on top. If I may add, this strategy is not that aggressive but its not for everyone to apply as well. But one upside of this method is that you will be left with enough capital to stay in the game and live another day. There is also a lot of online trading calculators around, you might want to 'simulate' things first before you go on the actual trade floor.