for the home-teleport, could there be a right-click "configure" that picks which group member's house you teleport to (when using spells or tele tabs). If that person isn't online it would default to your own house.
I'm also very excited for more shared group bank space, and a "Group house" if possible!
I think there needs to be a better change than just you can enter a team members house when they are online, but not in the house. It is so impractical that you have to have the team member online to access their house. There should be an update/improvement where you can enter a GIM members house when they are offline if permission is given. The house is where all your teleports are for the group, where the altar is and rejuvination pool. In my opinion and a lot of others I have talked to as well they want to access their group members house even if the house owner is offline otherwise they are waiting for them just to get on to use the house for game content. Please come up with a solution as this is a big problem for late game content in osrs.
I think any change that promotes GIM groups to help each other out is beneficial. being able to trade items and save each other from doing certain grinds is what GIM is about. While you have the option of trading in a Xerics talisman for tooths I think most GIMs would prefer being able to trade it to someone else and save them from the horrors of possible bad RNG.
Overall I like the other improvements like the house tps and group storage expansion. Great job to the team.