I'm building an anchor and instead of keeping a single account and use federation + memo, I'm sending my asset to each customer Stellar account. Today each user is managing their Stellar account and they are responsible for securing their seed.

I'd like to move to a model where each user don't have to worry about managing their accounts, my service will do it for them. 

Under this model, each Stellar account will be holding my custom asset and it will have just enough XLM for minimum balance and sending payments with my custom asset.