1. When the IMF and the OECD talk about structural fiscal deficits, you know their estimates are:

biased downwards thus indicating that the government fiscal stance is less expansionary than it actually is.
biased upwards thus indicating that the government fiscal stance is more expansionary than it actually is.
difficult to assess because their forecasts are subject to forecasting inaccuracy.

increases the financial assets that are held by the non-government sector $-for-$.
has no impact on the overall holdings of financial assets held by the non-government sector $-for-$.
reduces the capacity of the private sector to borrow from banks because they use their deposits to buy the bonds.

3. Historically, government debt has been used by central banks to manage liquidity and sustain positive short-term policy interest rates targets. This function necessitates that currency-issuing governments continue to, at least, issue enough debt to allow these open market operations to continue.