Based on my experience with FutureLab - I would recommend only registering a company after you have built the MVP/Product and it is ready to make money i.e. you are about to open a bank account. We set up our company 3 years before we opened a bank account which meant that we were paying for auditors and tax agents for a dormant company (wasted money)
About the co-founders agreement - I am not the right person to help you with this since we dont have a co-founders agreement for FutureLab. I launched FutureLab with my childhood friends Fung Wei (Also the CTO & Co-founder of GoGet.my) and Clarissa now the regional CSR manager of Grab.