The satchel charge is for blowing things up of course, but i wouldn't know the answer to your other questions. The light enhancing goggles probably give you better sight in dark places, but i prefer something more sturdy on my skull.
Like is said in the other thread, i stick to medieval weaponry. First of all, i always make sure i bring the Aikurn sword with me to the future, as well as that hook-like kind of thing you find in House de Hexe. All "aggrevated damage" items will travel with you to the future, as well as all special rings, amulets and insulated armour. I simply don't like to carry ammo around for my modern day weaponry.