Yes, flexible duct works fine for dryer venting. Sometimes, it may be the only option.
You should be using solid ducting for a range hood vent
Yes, your dryer does need a duct vent in the rear of the appliance. Certain dryers do not need to be vented, but they are marketed as such with a special filter.
Dryer exhaust can be to hot for a plastic type air conditioning duct. You should always use piping that is approved by the manufacturer of the dryer.
Condenser tumble dryers are becoming very popular because they can be placed anywhere in the drying area of your home and don't require connecting to a vent which goes to the outside of your house. Traditional vented tumble dryers do require a vent hose and therefore condenser tumble dryers are ideal for people who live in flats and apartments. A condenser tumble dryer works differently than a vented model in that the steam created in the drying process is condensed into water and collected into a water tank. An indicator on the dryer will alert you when the tank is full so it can be emptied. A vented tumble dryer converts the moisture removed from clothing to water which is expelled through a vent hose to the outside of the home. Some condenser dryers can be plumbed into your washing machine outlet system so the water can be pumped out through a shared route. Condenser tumble dryers are usually slightly more expensive than vented models but can work out cheaper in the long run as they can be very energy efficient as a result of the fact heat is recycled in the machine. If you don't want the hassle of installing a vent duct in your home, which limits where you can place your dryer, a condenser tumble dryer is probably your best option.
Not usually but there is a vent duct that does get clogged once in a while.
Duct tape or aluminum tape either can with stand the heat
A handyman, it is not a techincally complicated job.
Clothes dryer vents should be cleaned at least once a year, and more often if there are signs of blockage.Some signs of blockage are:Clothing takes longer to dryIncreased humidity in the laundry roomwhen the dryer is running, there is not enough air flow to the air vent outsidethere is visible dust clogging the outside vent.Lint blockages in dryer vents are a significant home fire risk.
It will not last, and could possible catch fire but that's a long shot. A hose clamp would be better. One to fit the dryer vent is probably $2 or $3.
Yes, you can hook two dryers up to the same dryer vent. You just have to get the right kind of hoses/ventilation so that both dryers feed into the same system with a split connection.
"Cover her mouth with DUCT-tape, so she doesn't scream."
I don't know about Illinois but check the Fuel Gas Code. I have never heard of PVC being allowed for a Clothes Dryer Vent.