Hi. I am getting ready to make some beds for a garden which is
currently grass. As the first step I was going to rent a sod cutter
and remove the grass (I have started it by hand, but I don't have 6
weeks to get it done), and then rent a tiller to turn up the soil
and/or mix the appropriate organic material into the beds. Since it
costs about $80/day to rent each machine, I then thought it might be
better to buy one (hopefully used) since I would probably end up
needing them on at least 4 occasions (that is if I can get
organized/plan far enough ahead), or more (if I remain dis-organized).
From there my question - I have been reading about tillers on the
web, but I have a couple of questions. Assuming we are staying in the
$600 Tractor Supply/Lowes range of rear-tine tiller, how would they do
at the following: (I know almost nothing about these machines)

(1) sod removal - setting it so that they only remove the top 3-4",
which I can rake/shovel to get the grass up
(2) breaking virgin clayey soil
(3) breaking a packed gravel driveway so that I can more easily remove
the gravel (sort of like #1, scrape the top 1" or so).

And some general questions about operation:

(A) Does the user control the depth by how much you let the handles
down, or is there a machine setting to control this? (i.e. some types
of stops on how deep the tines can do)?

(B) Does the machine move forward via the rotation of the tines, or
are the front wheels powered?

(C) if the tines move the machine forward, what about the counter
rotating tines and forward progress?

(D) if the wheels are powered, can we put them to other useages, like
snow plowing or grading stones or something? (I read about people
moving loads of soil and stuff like this, but it wasn't clear if this
was with a normal tiller or a super one (like one of the troy-builts
w/ a PTO)).

Thanks very much for your input,

don