For example a Near wallet with locked and staked tokens that release linearly for the next year and a half, Or a Flow wallet with staked and locked flow.
Can these be used as collateral here for a loan?
To be clear I'm trying to research as many details as I can before I ask for a loan, I've gathered that as a noobie, it's risky even to ask.
it's always better to ask.
It is not possible. Assuming your tokens are really worth something, and that they can be sold at any time
if something going wrong with his value or your loan repayment, you must provide the private key to the lender and you can no longer have access to this wallet until full repayments of the loan. that's the only way for the lender to be protected and that you can't selling tokens or sending them to your other wallet.