Since you spend so much effort to create this, the advice will be to do it the right way. I'm not sure any airlines have the API or anything similar to Google ITA, but scraping is not a way to go for sure. You will run into legal issue and getting C&D is not what you want. The data belongs to them and if you can get the consensus from them to use it then that will ease your trouble ahead. Maybe negotiate for a revenue share with them if you are really serious with your startup idea.
Please help me review: FlyNow.my