Homebrew PCBs

Okay,

I am about to take my first "real" etching tank for a test drive 
today.  There are a number of "Firsts" in this for me.

1) I am working with the powder, according to the directions, I add 
the powder to the water - 1 pound / 1/2 gallon.  They caution to add 
it slowly as it could react and bubble up or get very warm.  Any 
other worries at this point?

2) I will be using a small fish tank pump and bubbler rocks to 
create a wide spread of bubbles. This will be my first time etching 
with bubbles - I expect that this will speed up the etching process?

3) I also have a fish tank heater.  I am not sure if I will use this 
or not the first time around.  However, I have read the comments " I 
am using a hacked fish tank heater to warm the solution ".  This 
creates two questions for me.

3a) How hot do you need to make the solution?

3b) Do you really need to modify the heater to obtain the heat 
desired or can you use it without modification?

4) I suspect if I use any form of metal clip to hang the circuit 
board in the tank, it will probably corrode away and "waste" the 
ferric chloride.  So, I am thinking of hanging the circuit boards 
with wire (insulated), is this a good idea?

5) based on the above descriptions ( and any modifications you folks 
add), how long does etching take using this process?  I don't want 
to over etch, and trying to see though that brown solution isn't 
very good.  I will of course have to lift out the circuit board to 
check it's progress, but if someone can provide an approximate time 
that would be helpful in that I could detect if something is wrong.

TIA!

Chris