Learn English – A person who is trying to impress somebody

For your first statement I would offer: established

Most of the instructions are based on established information from a variety of individuals.

For the second: collective

Their collective experiences in the field define the way the business operates.

Although I would note that semantically, the second sentence is not quite right- Those experiences could help to shape the way the business operates or they inform the processes adopted by the business, but the experiences cannot, in and of themselves, define the way the business operates.

In British English a person is often called a mug if they have allowed someone to take advantage of them (it's a little like being the mark of a scam, but with mark you don't know whether the scam succeeded or failed—with mug you know it worked). I think it's a carney term.

You probably wouldn't say "I'm not your mug" but you'd say "I'm not a mug"—or "Do you take me for a mug?" or "What sort of mug do you think I am?"

American English gives us chump and sucker along the same lines.