What are the importance of negotiable instruments?

When endorsed (alt. spelling "indorsed"), a promissory note is a negotiable instrument. This is how banks fund mortgages--the promissory note is endorsed to them, making it a negotiable instrument...

No. Money is a non-negotiable instrument. All monetary instruments like currency notes or coins have a fixed value and it does not change every day. For example if you have a US $10 note in your...

A negotiable instrument is capable of being transferred by delivery or indorsement when the transferee takes the instrument for value, in good faith, and without notice of conflicting title claims or...

That it bear the signature of the person authorizing the payment or transfer.

No. They can be faked much too easily.