Got a feedback from devs
Klysmos, thanks for a feedback

It's pretty cool to see devs reaction at players suggestion!
Although I agree with your recommendations and it is best to promote more activity at britain bank the big problem is players get regularly killed idling at the bank and this is the biggest deterrent of idling there. With the various other ways of obtaining platinum (the daily event, paragons, events, voting), the risk of dying (losing fame, pvp points, anything you forgot to bank) and small selection of rewards on the platinum stone, more needs to be done to attract idling at britain bank. I've seen various players idle there, get killed (sometimes many days in a row), then seemingly get discouraged from idling there and not continue doing so. So long as there is an easy ability to kill players at the bank, it will be difficult to maximize idlers.
Although I macro-all-night pretty often there, I was killed near bank while AFK only once. After that I used simple razor macro to call guards and healing macro to heal with bandages @ bank box

Maybe someone tried to kill me after that - I don't know - but they didn't succeed
So if platinum for 'online-time' would be accessible only @ Brit bank ----> there would be more players with such razor macro ----> guards would be called much more often ----> griefer would be tired of dying often ----> balance would be restored... As it was @ UO in long-long time ago:
It works like this - if there are a small amount of players -- griefer could kill AFKers very easy. If there are a lot of players -- it's become much harder, almost impossible
As for now - maybe there could be added NPC-priest, who would patrol around Brit bank and sometimes heal/cure closest players?
Only allowing red players to get platinum for idling at the safe zone is a good idea to promote more reds to go there to idle. I think this should also be extended to karma gray characters as well, as otherwise they could be killed freely in britain.
Good point!
In addition to what has been recommended, we could also think about how to increase activity at the bank overall even for non-idlers. I'm open to suggestions on this as well as how to not make it so easy to kill idlers at the bank.
Another suggestions to motivate people stay @ Brit bank (and 'safe zone' for PK/greys):
— Add 'rest bonus' (like @ taverns in WoW). For example, every hour at Brit bank adds ~1.5 min to your next 'powerhour' (so it would be 30 minutes total for 24 hours bonus); Lore aspect also quite logical - Britain is the heart of the world and you recharge you power faster there. Or different approach - just give 5% bonus to skillgain near bank

— Add random raffle-like 'lottery' event with exclusive rewards - if you stay near Brit bank, every hour (or 24 hours?) there is a _tiny_ chance to get reward to your bank account. There could be several interesting rewards: collectibles, like rare coins, golden bricks, jewelery; and the most valuable reward - soulbound deeds for increase storage space at bank
