Assigning professions to characters

Many questions I need answered before I can decide which professions to assign to which of my (all too many) characters...

1) Are all materials and products tradeable?
I believe so yes

2) Can any character take on any profession and perform all its functions, or are there limits, direct (such as being unable to blacksmith items above your level) or indirect (such as all decent mining maps containing monsters that hit high)?
Fatigue is the only limit i can think of. You can make items above your BLACKSMITH lvl but with reduced change of success iirc, and all maps (Or most) have mining spots so it doesnt really matter

3) Do any of the character's base or derived stats affect its professional performance (for example: "hands" improving success odds, or "str" slowing fatigue). No, only personality traits may affect slightly but im not too sure. And no you cant slow fatigue and the fatigue recovery potion can only be used once a day
4) Do we get extra inventory space for crafting materials?
You get bags to store material collected by mining or plants, and these bags increase in storage size depending on your herbalist/mining lvl iirc

5) Are there materials that can only be obtained in specific, not-easily-reachable maps (in other words, do certain professions need to, or benefit from, staying in a specific area)?
Not really, most of the maps have materials to mine. There is also a special map in proffesion town with a time limit to get low-mid level materials too iirc

I've probably forgotten important questions, so if anyone has tips on how to decide what profession for which char(s), I'd be glad to read them.