Welcome to the real world.  First and foremost document everything that you see.  People goofing off, not showing up, what ever this "tampering" was, etc.  In the meantime start looking for another position elsewhere. 
Now by data I mean things that you can document.  You send out an order have a duplicate made and if there is any non-compliance get this followed up by documenting receipt of the order and any explanations why it can't be done.  Get everything in writing.  Same with orders to you ensure that they are in writing and if there is some reason that they can't be in writing the write it out yourself and take it to the issuer to sign that this is exactly what they want done.   Also put together a production record for yourself to show what it is that you are contributing to the company and any documentation you can put together for that i.e. new clients you've landed, records of what you have done, projects you've taken on, etc. things that will w
When you have every scrap of data that you can put together take it above HR to the owner, board, shareholders, etc. and lay it all out for them.  Tell them that you love your job but you can't work in such an unsafe environment as it creates a great deal of stress in your day to day work.  If the management of the company thinks that Aunt Ethel is better, than you could ever be, they will probably fire you but if you have someone who cares more about expanding their business than cousin Jimmy's feelings they may be willing to really look and bring about a positive change.
No matter which way this goes you are done (most likely) at this place because even if the top of the company appreciate you your co-workers will most likely rip you apart afterwards.