Chimera is a wallet in your total control. Chimera Wallet does not charge any fee or subscription for the use of the application ever.
The third party services you can access via chimera might charge fees and have they own policies please check the individual policies and terms of the services available trough Chimera Wallet.
The transaction fees related to P2P protocol are automatically paid and none is retained by Chimera but only used for the payment of fees as part of the transaction.