The brown scum on the first two images could just be tannin from black tea. You can peel this/ the stained layers off the scoby. You can avoid it next time by not letting the tea "stew" i.e. removing the tea bag sooner (you might also need to use a water filter).
You can increase the yield with a bigger container. It needs to have a wide mouth to maximise the amount of surface exposed to air relative to the volume of liquid. I personally find my kombucha too acidic after a week so need to dilute it in a closed secondary fermentation (to fizz up) which doubles the yield.
Salt, Fat, Acid, Heat by Samin Nosrat does this. It begins by introducing the eponymous 4 elements at length then provides a decision tree to help you work through the recipes at the back according to the gaps in your experience.
It's not specifically focused on Indian food but does contrast flavour profiles from different countries. For British Indian Restaurant Curry I'd recommend Dan Toombs "The Curry Guy". It's not written like a textbook but I've learned loads of tricks from it (e.g. base curry sauce/ freezing fried paneer for later, yoghurt marinades etc).