please find below a more detailed explanation regarding your questions:
1. Yes, setting number of rings to 1 means 7 macrocells, one in the center and 6 in the corners. The reason why the outer sectors of outer macrocells don’t form a hexagon shape is because the region of interest is a square. This region is not infinite but it depends on the number of macrocells set by LTE_config.nr_eNodeB_rings and on the inter-site distance between them set with LTE_config.inter_eNodeB_distance. Increasing the number of rings will always produce such behaviour for the outer sectors of outer macrocells.
If in particular you want to take care of interference influence more accurately, then I recommend to use parameter LTE_config.compute_only_UEs_from_this_eNodeBs = true, or in case of macro and femto put the indices of each cell located in the center, e.g, LTE_config.compute_only_UEs_from_this_eNodeBs = [13:15 first_center_femto_index:last_center_femto_index], as indicated in the launcher file. This will generate all eNodeB_sector-user parameters, while the evaluation of results will only consider users located in the center of the region of interest (excluding the outer sectors since the users in these sectors get less interference due to boundary positions.)
2. Regarding map resolution, I tried a simulation with 10 meters/pixel, and it produces 10 femtocells in each eNodeB-sector. Maybe check the distribution of femtocells and their positions before plotting!!
In case you can not solve this issue, send me the launcher file and config file with parameters that you are using for your simulation.