Hi Abisheik,
(1) I think the best configuration is depends on the problem. Experiment and choose what you find better suits the problem. If you do not have a criteria to what suits your problem, I would suggest to continue using the Centroid, the Minimum (or AlgebraicProduct) as implication, and the Maximum (or AlgebraicSum) as the Accumulation.
(2) I think this depends on the problem too. Just remember that the output is fuzzy, and you are choosing only a part of the output to represent it. I think with this method you also lose information, as you are ignoring the membership functions of the other terms. Just be aware of this.
Cheers.