Whats the point of those magic sticks/wands? What are "charges" that they need to be used?
Whenever an enemy casts a spell near you you get a charge. The more charges you have, the more health and mana is restored when you use the stick/wand. Magic wand is an upgraded version of magic stick which gives you a few bonus stat points as well as the active ability.
Why are there neutral enemies? Isnt it easier to gain gold just through killimg creeps?
Neutral enemies are at a basic level just more gold and xp (and some give less + more than lane creeps), but they serve deeper purposes too.
Neutrals can be:
1. Jungled. Instead of laning, certain heroes have the combination of abilities that let them farm neutral creeps instead of lane creeps, which means that your team gets more experience in lanes as there is one less hero sucking it up.
2. Pulled to the lane, in order to bring back the "front" of battle in that lane closer towards your tower and deny the enemy team xp. Heroes aggro the neutrals into the lane, which are then attacked by the lane creeps and pulled back into their camp where they are killed. Heroes can also use this as another way to take advantage of the additional gold+xp available in the jungle to give the more bountiful lane gold+xp to important heroes on their team.
3. Stacked. Creeps will spawn in the camp if it is empty every minute, so if you aggro the creeps out of that camp at specific times it will be stacked with more creeps. This is another source of extra gold+xp.
4. Farmed when no enemy creeps are on safe places in the map (for you).
5. Converted, so heroes can control the creeps as friendly units. Some neutrals have useful abilities which heroes like Chen and Enchantress take advantage of (as they have skills to convert creeps). The hero known as Doom can also steal the abilities of neutrals.
There are particularly powerful neutral creeps called ancients which are worth quite a bit more gold+xp than lane creeps. Typically these will be stacked so a hero can farm them for a lot of gold.
What does the matchmaking look for? How is skill calculated when MMing?
Nobody knows. Presumably it's similar to an ELO style system, which updates your skill based on the results of matches and the skill of the players you played against.