We currently test rules manually and post results here: https://help.coinrule.com/en/collections/2700051-template-ru... and also in our community on telegram. The automated backtesting is coming later this year - correctly capturing for slippage is tough; we will be using historical order book data provided by Kaiko to make this as realistic as possible though
Good question - I'll jump in for Gab as its his mum's birthday today :)
With fixed fee pricing we are seen by regulators as a Software provider rather than a trading platform. The other point is that user funds sit on the exchanges and we have no withdrawal rights for greater account safety, so it's easier for us to just charge a fixed fee.
I would argue that the efficient market hypothesis is problematic at best and I also disagree with the characterization of our users as 'dumb money'. We are in fact quite lucky to have some very smart users with us. There are many ways you can use Coinrule, not all of them must be entirely short-term oriented!
That said, it's absolutely your good right to disagree with our value proposition.
In the beginning we were making 8-12% a month, just arbitraging derivatives so very low risk (except platform risk etc). But after a few months it started shrinking, and shrank down to 2-3%. Still very good for a traditional fund when annualised, but we only managed a few million from friends and family so it didn't really make sense for us financially any more.