The battery question is fairly easy. When in a low state of charge batteries can accept a high rate of charge, 10A for a 100Ah battery is fine, the average car alternator will push 70 or so amps into a battery smaller than that. You need to reduce the charge rate when you have completed the bulk charge and the controller normally does that by limiting the charge voltage to something in the region of 14v, the battery then charges at a current which falls as it becomes charged.
The earlier questions are difficult, I think you are confusing several things. The load on the battery has very little effect on the charge produced by the wind turbine. The leads to the inverter need to be short and heavy, the lower the volt drop there the better.
The situation with the turbine is rather complicated and the answer really depends on the turbine. Any volt drop in the cable is a loss, but reducing it to very low levels may or may not be an advantage, the whole process is complex. Your turbine will only produce battery voltage at cut in, at the wind speed needed to give significant power out the blades will need to be running well above the cut in speed so the open circuit voltage may well be more like 36v. This open circuit voltage is the emf. When connected to the battery the battery end will be at nominal 12v. Some volts will be lost on the cables and the rest will be lost in the alternator windings. The current that will flow will be (emf - battery volts) divided by the circuit resistance.
If the alternator is very efficient ( low internal resistance) and the cable loss is low, you will stall the blades and the prop will develop little power. You have excellent electrical efficiency and dreadful prop efficiency and the result will be a disaster.
If the electrical losses are higher the prop will spin faster and produce much more power. There is an ideal electrical loss that will bring the prop on the peak of its power curve. If you are at this point or running faster, adding extra cable loss will worsen the situation and expensive cable will be beneficial, if you are way down in the prop stall region then increasing the cable loss will actually improve things, so it all depends on the alternator you have. If it is a really poor thing then keeping cable loss to 3% may be sensible but in many cases you will get better results with more cable loss and up to 10% may not be detrimental.
You don't actually say what turbine it is but you give a few clues and I am afraid I suspect the alternator is so dreadfully inefficient that the very expensive cable may be beneficial although even then it may only make a few watts difference for a given wind speed, sometimes you have to choose between the ideal and what is realistically cost effective.
Flux
