Hi Donsports.
I hear you on the pinpointing problem. That is something that drove me to despair till I learned how to pinpoint with it. Don't give the pinpointing graphic too much credence as it will only tell you that you have a target under the inner coil somewhere. Khouse is right. The 70 will auto detune, which should help a lot. I use the X-Terra 30, which doesn't seem to have this function, so I can give you a couple of other tips that help.
You can manually detune the detector. To do this, you can simply just raise the coil an inch or so, while in pinpoint.Or if you have gone over your target in pinpoint, while holding the coil centred over the target, press the pinpoint button twice more. these will shrink the target down to a couple of inches.
The second technique that I use (mostly) is to go over the target in pinpoint. Once I think that I have it centred, I slide the coil towards myself till I lose the Signal, then push it back till I just pick it up again, then wiggle it side to side which helps in telling me the exact location of the target. (At the 12 o'clock position of the inner coil.)
As to your detector shutting down, it is only a minor problem with the springs in the battery compartment compressing a smidgen too much, causing a contact break. It's easily remedied via several choices. You can send it back to Minelab to fix, which a few of us have done. You can try a different brand of battery, which some have also down (some brands a slightly different lengths) or if you trust yourself, you can VERY gently tease the springs out a little bit. I and a number of other folk on the forum have had this happen to us. Very annoying when you don't know what is going on, but once solved, you'll enjoy a great little detector.
Good luck.
Mick Evans.