Things like loans are basically impossible in EVE since collateral is pretty much impossible to handle with game mechanics in a way that won’t cause the lender to get left holding the bag in some capacity. Which is unfortunate, since with the really strong industry aspect of the game industry players could legitimately pay fairly solid interest fees and can often get cash flow crunched.
However, there is ONE thing in the game that is nearly impossible to destroy or transfer: skill points.
With extractors, skill points already can be turned into a commodity with an isk value. Furthermore, with the new clone mechanics skill points can’t be destroyed or transferred except via some very narrow set of mechanics (character sale, biomassing, extraction, and T3 cruiser destruction).
Add a loan mechanic with payment terms. Having a loan flags the character as being unable to extract skill points with normal extractors, be biomassed, or be transferred. Just remove the T3 subsystem skill loss mechanics as a failed gameplay system, or don’t allow those skill points to be counted in the collateral.
If the player with the loan doesn’t make their payment via the loan interface, the lender now has the option to remotely use a skill extractor on their character. Have an option where the lender can give up/reset their extraction rights until the player with the loan violates the loan terms again (i.e. you are late, initiate a transaction with me where you pay me what you owe plus a penalty we agree on in exchange for me revoking the extraction rights I’ve got on you due to you missing your payment).
Maybe even allow a two stage system of collateral. Like, if I violate my loan, you get these 5 ships and blueprints located in X station. If and only if those items are not present for the loan system to impound or sieze, then and only then do you gain the right to extract skill points.