The slew of crimes began in January last year when he went to a wrecker's yard with two 16-year-olds and stole a car.
They then filled it with $50 worth of fuel and drove off without paying for it.
In explanation, Keen said he planned to use the vehicle to run someone off the road - ''to scare them but not to kill them''.
But Judge Crosbie deemed the most serious offence a theft in May.
Keen went to stay with a family in Mosgiel.
In a statement before the court the victims said they did not judge the defendant despite it being clear he had had a hard life.
Keen repaid their kindness by fleecing them of more than $6000 of household items.
While the family slept, the defendant scoured the property.
Keen's vast haul included: bottles of alcohol, five cellphones, numerous DVDs and CDs, two cameras, a speaker, three televisions, a laptop bag, games console, a jewellery box, two sets of binoculars and headphones.
Then he moved on to the garage.
Keen filled a sports bag with frozen meat and fish, took sports equipment and a car battery.
The assorted goods were hidden in the garden and he picked them up later in a borrowed vehicle.
Keen explained the son of the homeowners owed him money.
He described the offending as ''reasonable'' and argued it had not hurt anybody.
The judge, though, said Keen had caused significant pain during his career in crime.
''Your life to date has been extraordinary in terms of the damage you've caused other people,'' the judge said.
Keen was jailed for nine years in Australia in 2007 for attempted murder after luring a teenager to an abandoned prison before stabbing him several times and dropping a large rock on his head.
''All in all a significant criminal history and one that in real terms means that you've spent little time in the community as an adult,'' Judge Crosbie said.
While Keen's background explained some of his anti-social behaviour, it did not excuse it, he said.
The defendant was jailed for two years and nine months. He was also ordered to pay $4798 reparation.
