1) Yes, almost always
2) I believe so, as it would constitute a technical default, even if agreed
I am not giving the moral reply (I empathise with you that such replies are not helpful), but are you currently able to make your repayments, even from your savings? It is an important question, because if you are currently making (or are capable of making) your repayments, you have no hope of getting any of your debt forgiven in a settlement.
Again, nothing to do with morals, but why would the banks write off a portion of your loans if you can afford to pay it? Even if you have now geared yourself to a level you are uncomfortable with, but can still get by, then you've no leverage that I can see. If you can't make the repayments, that's a different matter.
If you have the cash to "settle" some of the loans, then the bank will judge that you have the cash to make the repayments from youyr savings for the time being. They will clearly distinguish between can't-pay and won't pay.
One exception: If you have a giveaway tracker mortgage, but have the money to clear the capital sum off, you might have a chance. If it is costing the bank more to fund your mortgage on the money markets than it is getting off you in interest, they might listen to an offer - it could save them (and you) money. However, I have only heard rumours of this happening, and have not seen any concrete examples myself.