Is 64GB storage enough? They do come in 256GB as well
I would say 64GB is definitely enough for Tagtooling and most casual creative use cases.
How do I connect the ipad to a windows laptop? through a 'lightning to USB' cable?
I'm a Mac user myself, but I believe this is correct
If I go mobile, I need some portable powerbank for the projector, right? Any advice?
For mobile use we usually use a car battery + power inverter, or a small generator. For small scale projections you can get a battery powered pico projector.
i look into that mirascreen, but for that you need wifi? I'm planning on projecting on all kinds of events, with and without wifi...
Yes for multiplayer and AirPlay you need Wifi. We use a compact Wifi router for our mobile sessions. Sometimes its enough to create a hotspot with a laptop or phone.
a connection with a laptop seems vital if I want to combine it with other software and image sources, but how does a laptop makes connection to the tagtool output?
Currently the easiest way is to stream from the iPad to the laptop using a software called AirServer. AirServer runs on you laptop and can share the Tagtool image with other VJ applications using Syphon. We plan on adding other ways of combining the output with other software in the future.