Cutting an electric fence is easy.... just get bolt cutters or hedge trimmers with long wooden handles... done deal....wood is an insulator.
YES, if you simply manage to connect a hot wire and a ground wire with any sort of electrical conductor, the ENTIRE fence is DEAD..... I know this to be true from hundreds of experiences... where a deer or other critter got into the fence and left a ground and hot wire twisted together. Another problem is limbs falling on the fence and pressing hot and ground wires together...this WILL be a problem in your case since you are running the fence thru wooded areas... thus, will need to check the fence regularly.
I cannot recommend too highly high tensile wire..either smooth or barb. You can stretch that stuff until it sings like a piano wire. To use it, you need to know these things....if you already know them, great, else PM me and I'll send you URL's that explain.
how to tie a knot in high tensile wire....trust me, there is a special way to do it.
ratchets that stay in the fence, one for each strand, so it can be tightened as posts give and slack develops.
how to make extremely strong corner braces...so they don't give
how to find a high impedance electric fence charger... one qualified for about 200 miles of fence..... don't be fooled...I enclose about 200 acres with one and this level of strength is necessary, lesser strength chargers will poop out when grass, brush, limbs are against it... worse in a rain...chargers are rated in jules... get the strongest one you can. This is NOT a weed cutter/burner, rather it puts a very strong pulse on the wire for a very short period of time. The charge does not burn or permanently harm a person when they touch it... rather muscles all over the body contract and you are uncontrollably spasmed... often falling to the ground... I truly know this to be true from personal experience
These chargers some in 110 and 220Volt capability.... get 220 if you can. Cost will be about $400.
I consider you have two fence options....
A single strand, electrified. The ground itself is the return path. Person puts hand on wire, charge travels thru person toward ground, which is thru the shoes. This involves the entire body in the electrical shock. There is no other wire to ground the fence out if a limb falls on it. Only way to stop the electricity is either cut the wire or locate a wire and wrap it around the hot wire and metal post to ground it out. Wood or fiberglass posts solve this problem.
Yes, touching a single electrified strand will shock... ground is thru body to feet. Touching a electric wire AND a ground wire ... the path is from the electric wire to the part of the body touching the ground wire.
Multiple strands, some hot, some ground. This is really primarily a people fence that happens to be electrified. It is extremely simple, for the knowledgeable, to ground it out... pick up a stick, twist a ground and hot wire together..done deal... now just proceed thru the fence as if it were not electrified. Inconvenient, not hard for the determined.
My recommendation would be for the single strand...cheaper, marks your boundary, a place to hand signs, no convenient ground wire, a determined person will be able to get in, regardless of how many strands are there and you will have to apply your chosen confrontation technique to them, anyway.
More questions, ask 'em.