Since clan bank accounts normally remain at 0 qi, there should be an actual clan bank where there is no qi restriction on items so players can freely donate whichever items they want to. This would also make a possibility for marketing high qi items between clans, even if the players don't have the requirement for wearing the items. I know the idea is a bit flawed but with some adjustments I think it would make clans more interactive in item trading and selling.

I like this idea but to be honest I have not seen anybody really use the clan blanks lately but I wouldn't mind ACTUAL BANK ACCOUNTS for your Toribash character where you can setup a bank and store TC so you don't end up having the need to spend it all.

This idea isn't as terrible as most of the other suggestions we get in this board on a daily basis.
I believe the implementation of your suggestion can be beneficial for clans aswell as the rest of the community, by way of hosting tournaments and major events.
Of course, if the bank doesn't meet the required Qi amount, there should be a fee to send it to said account. In the event that such an item should need to be transferred to a user as a prize for winning a tournament, admins could give the bank the ability to send to a specific user, after receiving sufficient proof from the clan's leader(s)/co.leader(s) to proof that person x did infact win the tournament.

You can open a shared bank with one of your members' accounts (someone who has most QI) using the tool on forum. This actually is their purpose.