You seem to misunderstand how the mechanics currently work.
The assets can still be transferred to another structure in the system after 5 days, and before 20 days have elapsed, for free, as it is now in the mechanics.
They are only automatically moved to LS if you dont transfer them in-system to another structure, within 5-20 days, as is now in the mechanics.
Currently, it costs nothing to recover assets from another structure in the same system, if transferred there by players through asset safety.
In everycase in the change, you will have to pay to recover them there.
Asset recovery will thus always cost isk but not the asset transfer.
Asset transfer, and asset recovery are two different things. Transfer remains free, recovery does not.
And the cost of that recovery is currently far too low, and can be zero, at worst.
Yes.
Helps to think of it as if there was an NPC corp with the business of clearing assets out of structures being destroyed and moving them to safety, and then sells them back to the owners at a profit.
If youve seen the Storage Wars series, sort of like they buy out abandoned storage on firesale, and then sell them back to the owner at a profit.
I like your sliding cost suggestion also.