1. If you change variation assignment weights without making a new phase of the experiment, the data quality checks will start to throw warnings.
2. For data, we recommend at least 1 week of data, but for numerical limits for calling an experiment, it usually 'depends'. We give you both the risk and the chance to beat control - and one or the other (or both) can be used as your determining factors to end an experiment. Bayesian statistics is less susceptible to peaking problems, so its okay to look.