I care for dozens of Guzmanias in low humidity environments where misting is not practical. They have proven over time that they do not require high humidity as long as the soil is kept properly moist. In nature, these are epiphytes that have their roots attached to the outside of damp tree branches and collect water in their cups. However, when they are potted up and put in soil all of that changes. The plant can now absorb water very well through its roots and no longer need high humidity or water in the cups. Do allow the top quarter of the potting mix to dry before watering.
The offsets can be removed or left in place. It may take several years for the mother plant to completely die back. Remove discolored leaves as they deteriorate.