1. there is no requirement for SIMAs to have ARUCO Tags. You cannot use ARUCO Tags to locate the SIMAs of the other team. The SIMAs will be tested for obstacle avoidance during homologation. This might be done by placing some cubes of 60mmx60mmx60mm.
2. as they are not to be released within the first 90 seconds, there will be nearly nothing to test. It depends if you choose to move within the first 90 seconds inside the starting area, which I would not recommend, but you might be allowed to.
3. the stand number Tag is a sticker provided by the organization of the contest. It might be similar to the stand number sticker for the main robots. It is not really something for robots to identify opponents by.