MabiPro: The Authentic Old-School Mabinogi Experience

Hi, I recently downloaded the game and I got a few questions.

1 - I wanna to be able to fight and heal, so, I thought about leveling melee and then level healing and party healing. Is it a bad choice and should I stick to mage stuff?

2 - I read a little and as far as I understood I should use 2 swords or two-handed sword as a human. Why can't I use a shield and a one-handed weapon?

3 - If I go to the magic route, what should I level besides windmill?

4 - Is there any point in using acessories? I can't use them while wearing a heavy armor but they seem weak and expensive.

5 - I like to train profession skills such as the life skills in the game. Is there anything I should focus? I plan to level them all after getting good enough with the combat skills but I plan to level the most important one first.

6 - All heavy armors give the same stats or am I reading something wrong? I checked the 2011 wiki and they all seem to be the same in stats but look different.