SO, you'll probably be hearing alot of these questions from me... just warning ya'll

anywho

What would happen if you put mercury in an Incandescent lamp? would it function much like the halogen lamp where it helps keep the filament running longer? or would it do nothing? I'm talking about higher wattage lamps by the way... I'd assume lower wattage lamps would not heat up enough to do much of anything

It would transfer heat from the filament, but i dont think it would do anything else

Might make a brighter flash at lamp EOL

It will form a discharge even at normal lamp voltage, so flashover and kaboom...
Definitely the mercury won't increase the lamp life at all (except slowing down the vaporized tungsten diffusion, as all other gas fill does - there the heavier rare gases like Xenon or at least Krypton are way more efficient in terms of the diffusion slow down capability vs heat transfer design trade off). The halogen fill really helps by the means of real chemical reactions (the halogens react with tungsten at colder temperatures, but dissociate back to elementary form under the filament heat, in other words it chemically dissolves the tungsten deposited on the bulb wall, but return it back onto the hot filament)

But it won't flash over until the filament fails, as that is the path of least resistance so long as it's intact, but it would make EOL interesting, and they would also be banned in Europe.. 

But it won't flash over until the filament fails, as that is the path of least resistance so long as it's intact, but it would make EOL interesting, and they would also be banned in Europe.. 

Well, that is true only when the lamp is designed so, the electrical field does not ignite the discharge. That works quite well with classic lamp fills (well, the 230V lamps need to have the fill composition engineered to reach the required strength), where sufficient gas pressure makes sure that arc ignition voltage is high enough.
But the mercury condenses when it is cold and that means you can not build up any high mercury pressure, plus the mercury is easier to ionize.
This effect is used in many discharge lamps (old ozone generation lamps, the old GE S1 and S2 "sun" lamps,...) - the filament just on the lead wires is thicker and serves as main electrodes, then the middle section is thinner and its purpose is just allow the current to pass and preheat the electrode sections.

The Mercury does not make the pressure go down (comared to the Argon fill alone)

Actually if the pressure is high enough it does not arc.  In the 1970s/80s Sylvania experimented with mercury-filled halogen lamps. 

Quite a lot of the metal was dosed into high power lamps like the DZV, BVD, A1/265 overhead projector capsules so as to increase the pressure in the capsule beyond what could be attained by freezing in the noble gases.  Due to its big atoms which are not very mobile at high pressures, mercury vapour has quite high viscosity and relatively low thermal conductivity, which reduces heat losses from the filament (just like how xenon filled lamps are more efficient than krypton or argon).  The result was a lamp having higher efficacy and/or longer life.  However sometimes mercury mirrors would form on the quartz and block the light.  This was ingeniously overcome by using lamps having grid filaments with a proximity reflector on one side.  That directed most of the light (and heat) out one side of the capsule, and raised the bulb wall temperature enough to vaporise mercury out of the light path.

Despite fairly positive results these lamps did not go beyond field trials with some O.H.P. manufacturers and were not sold.  Such lamps require forced cooling to achieve long life and that made the mercury-halogen types difficult to control.  They also tended to explode due to the high internal pressure - and unlike an HID lamp where the mercury vapour is hot enough to be instantly oxided and rendered fairly safe, the mercury-halogen lamps would discharge a poisonous cloud of metal vapour when they shattered.  So it was a nice lab idea, but not really possible to do in practice.

That is an interesting bit of insight James, thanks for sharing that... Never knew they actually did extensive testing on this idea

I've always wondered about blue phosphor coated halogen lamps, since halogen produces some uv , i would hope that it may make the blue phosphor glow and make the lamp have a higher colour temp

What about a UV lamp? I've seen filament lamps with mercury in them to produce UV.

A self ballasted Mercury Lamp is very close to that idea!