Just on the whole no fee / small fee, there will probably be a discussion going on about wages. Obviously Robbo is only guaranteed LFC wages for another 12 months, so the fee issue will be around whether Atletico pay a fee and ask us to subsidise the wages by making a termination payment to him, or whether we agree to release him and they fund all of the wages. Either way, given his age, it's unlikely Atletico will be paying him LFC money.
That said, I don't think it's unreasonable for us to expect a fee for him, likely with add-ons.
If we were to terminate his contract, we'd need to pay him off (albeit probably at less than full whack because he'll agree to a compromised amount, taking into account what he'll earn at Atletico) but it also means we wouldn't be transferring his registration, which means there is nothing to which we could attach add-ons. So I don't see the contract termination as a realistic outcome here.