House purchase with full financing / hardly any equity / option: inheritance with debts?

Mama's rental income must also be taxed. Maybe a gift with usufruct rights makes sense? So that she can continue to live there rent-free.

Well, if appropriate investments are made in maintaining the property, then not much tax remains, if any at all. Mom doesn't have to pay the full rent.

However, it would only really make sense if the thread starter also takes over the debts and can claim them for tax purposes.