If they are frozen, they will be safe for a long time. I would not recommend vacuum packaging your own food for refrigeration. If you are referring to commercially packaged products, go by the processor's recommendations.
No. In fact, they'd be quite dangerous.
open or unopened? if unopened it will be safe to eat long after your dead
If it's packed in a vacuum sealed can, such as an Armour Star Ham, it will last an incredibly long time. The can is dated, but WW1 canned rations were opened not so long ago, and were as edible as the day they were packed - and this was with early 20th century canning methods which are inferior to today's! However, if the can is dented the canned food shouldn't be kept for long. Also, if the can is bloated it should be discarded immediately. If you freeze a vacuum sealed ham (plastic wrapped and airtight) it should last at least a year if kept frozen below 10 degrees Fahrenheit - but below 0 degrees is ideal for the longest storage.
Depending on how long they had been left out would depend on how safe they were to use.
All vacuum materials are safe and non-carcinogenic as long as they are properly maintained and serviced by authorized service centers.
The Miele S5980 vacuum is NOT a wet vacuum and would not be safe to use with drink spillage.
The acids found in foods, such as citric acid and lactic acid, are safe to eat because they are components of the foods, and the foods are safe to eat.
Most foods should be safe for 3 - 5 days if stored in the refrigerator.
Freezing will keep most foods safe for a long time, but from a quality standpoint, many foods will not taste good after extended periods of time. Guidelines on foodsafety.gov recommend freezing various foods for anywhere from 1-2 months up to a year for best quality.
Very short term: create an explosion, in a safe area. Long term: settle on a fixed small sized suitable area and suck the air out until the vacuum is no longer needed.
yes
Yes, it fine as long as you are comfortable with it. It may cause heartburn.