Minhogei Aveilus

I was looking throught the Minhogei Aveilus on the Moreshet Ashkenaz webiste, and have a number of questions:

1) We normally find in Minhag Ashkenaz that Qel Erech Appayim is skipped on less days than Lamnatzeach e.g. Erev Yom Tov other than Erev Pesach IIRC. Why is Lamnatzeach said in a beis avel, yet Qel Erech Appayim is omitted?

2)The strict reading of the wording on the webpage sounds like Vihi Noam, V'attah Kadosh, and V'yitten L'cha are all omitted on Motzaei Shabbos, but Shir Hammalos is recited after havdoloh as usual. Is this correct, or is Shir Hammalos skipped like the rest of v'yitten l'cha?

3) The webpage says that the Ovel leaves the room when Hallel is recited. Does the Ovel recite hallel on his own outside the room? (I would think he must at least on Chanukka since hallel on Channuka is a din.) Furthermore, does the Avel daven for the Amud in the Beis Avel during the rest of Shachris? If not, what about Mincha and Ma'ariv of Rosh Chodesh and Channukah? What about other days when Tachanun is not recited?

4) The webpage says that the Kerovim of the Ovel cannot do laundry when they need to show miktzas Aveilus. Does this include wearing a beged m'chubbas?

5)The webpage says someone in shloshim may wash with cold water. May he use soap or shampoo?

6)When we say an Ovel who is Muchshar L'chach is encouraged to be a ba'al tefillah during shiv'ah (at least during the last days of shiv'ah) and during shloshim, does this apply to an avel who is not the child of the niftar?

7)Is the Ovel forbidden, permitted, or encouraged (meaning we try to be mechabed him) to lead the zimmun during the shiv'ah itself? What about on Shabbos during Shiv'ah? What about on Shabbos and Yom Tov during Shloshim or Yud Beis Chodesh? Im Timtzei Lomar that he isn't singled out (or isn't permitted) to lead the zimmun on Shabbos and Yom Tov, what about other days when tachanun is not recited?

8. Why do dinei Aveilus not apply during a maggefah of dever? Am I correct that this is only true for Shloshim and Yud Beis Chodesh, but that the aveilus of shiv'ah still applies?

9)The webpage says that the kerovei Avel wear the beged Elyon of Chol during the Shabbos of Shiv'ah. What does the Ovel himself due? Does he wear all bigdei chol or only the beged Elyon? What about an Ovel during Shloshim?

10) When does the time of an ovel for one's parents moving one's seat in shul expire? The webpage first says 11 months, but I'm guessing that it's supposed to read 12 months, because the next section goes onto say that in a leap year this practice is observed even in the thirteenth month. Am I correct?

Thanks for all the answers to these many questions,
Melech