You will have 100 touch points per Tile unit, up to a maximum of 254 touches in total. The maximum amount of touches is a limitation of Windows 10. It may vary in other operating systems according to their specifications.
Yes! You can use the Tile:
You can use up to 6 TAGs per Tile unit. For example, if you have two Tile units, you can use 6 TAGs on each Tile, however, you're limited to 6 ID's.
USB hubs can cause power consumption and USB communication instabilities over time, it is important to choose one offers stability. Or, instead, use active USB extensions and/or USB expansion boards (for the computer).