Someone told me today that I really should put up plastic (like 6mill poly) on the interior of my home, just under the sheet rock.

Ive used TF forms, 2+" on the interior and 4" on the exterior.

Is this something I should do ? 

PS I live in northern Maine with very cold weather.

No, not necessary. The foam and concrete forms a very good vapor retarder already. The reason for the poly in stick construction, in very cold climates, is to prevent water vapor from migrating through the drywall to the outside. It will condense somewhere in the interior of the wall creating moisture problems. Poly used to be recommended for most of the northern half of the US, but newer knowledge has determined a vapor retarder, not barrier, is best. You want the wall system to breathe so vapor can move in and out. There's no doubt in my mind that the foam thickness ratio you used will keep the temperature of the interior surface of the concrete above the dew point.

For more info go to www.buildingscience.com and read their recommendations for building in cold climate. I know there is a climate line, north of which a vapor barrier is recommended. You may be above the line, but even then I don't think you want poly for an ICF wall.

Thanks for the advice, appreciate it...checking out those links now.

Another reason not to put poly over the ICF is to be able to glue your drywall to the foam. Using adhesive will reduce the number of screws needed to fasten the drywall and not force you to place drywall board joints directly over the ICF anchor strips. Make sure you rasp out any humps and dips in the ICF wall and clean off any powder before applying the adhesive.

I actually have strapping up on the interior to attach the sheetrock too when the time comes, I was thinking it would be MUCH easier to wire it this way as i could hang the wire in the middle.

Thoughts?

Your wiring may be easier depending on how thick your strapping is.  I believe the NEC and residential building code requires the wire to be 1.25" from the edge of the stud or rafter.  If you only used 1x strapping, you are still going to have to cut grooves in the foam but not as deep.

Correct. If the wire is less than 1 1/4" from the edge of the stud (i.e., from the back surface of the drywall) you have to cover it with minimum 16 ga steel.