1(Where do peyos/peyot begin (behind the ear, top of the temples … different groups have different styles (yemenite, Breslov, Bobov, hareidi etc.)? And what is the proper length? 2) The use of expensive European black hats costing several hundred dollars and Italian made expensive suits (with buttons right over left) in a caftan style in black,no disrespect is intended, has nothing to do with Jewish history of our dress code. Why is the custom (black is a color of mourning of the destruction of Beit HaMikdash)? Bedouin dress is closer to the historical way ancient Hebrews dressed, is it not? 3) Beards-some grew them long,other trim,others shave-what is a proper way? May one trim a mouthstache?
1) The different styles of pe’os are but a question of style and custom, but certainly not a question of halachah.
The basic obligation that there should not be a hair-free line from behind the ear to the forehead. This means that the top part of a man’s beard (his ‘sideburns’), reaching down (according to Shulchan Aruch) to the point on a straight line with the bottom of the earhole (where the upper jaw meets the lower jaw), must not be shaved. The length at which the hairs must be left is the length that is sufficient to bend individual hairs back on themselves. This would be approximately half a centimeter.
If the sideburns are left intact as they must, the question of how much hair to leave dangling down (from above the sideburns) is a matter of tradition alone.
2) Chassidim in particular, and Chareidim in general, choose to freeze nineteenth century European fashion, and bring it into the 21st century. They do this primarily to maintain a “separation” between themselves and the non-observant surroundings. It is true that the color is generally black, but we can at least be thankful that shirts are an exception to the rule. There is certainly nothing “holy” about fur hats, and there is nothing “holy” about Bedouim dress either, even if our ancestors wore it.
3) There is no “proper way.” Please see here. It is certainly permitted to trim the moustache, and even those who “do not touch their beards” trim their moustaches, with the exception of Chabad chassidim (after speaking with some Chabad followers, it appears that they, too, do not know why they should not trime their moustaches, but refrain from doing so because this was the practice of the last Rebbe).
For Pe’os, see Shulchan Aruch, Yoreh De’ah 181:9; Beis Yosef and Bach, 181; Rambam, Laws of Idolatry, chap. 12, no. 3 (Rambam has a different definition of how many hairs must be left); Chasam Sofer no. 139.