Is it ok if i am reading madd munfasil four or five harakat and madd al arid alsukoon with two?

Question
Assalamo alaeykum
May Allah acceept your work and give you strength to continue it.Ameen
I want to ask you about
(1)is it ok if i am reading madd munfasil four or five harakat and madd al arid alsukoon  with two? i heard sheikh Manshawi(Rahimaullah)recitation and also my sheikh(May Allah protect him) told me it is fine.
(2)I read your list of words which you have mentioned in Tayyibatun nashr (Qasr munfasil) that it is must to do sakt in four places while i heard Sheikh Mustafa Ismail and also Sheikh hussary (May Allah have mercy on both of them) recitation that they read with idgham in surat qiyyamah when they are reading with Qasr for mufasil.
(3)Can you tell me any book in English which describe about Hafs an asim min tareeq shatbiyyah and also a book on Qasr munfasil.
please forgive me if i wrote something wrong and for many questions.
jazakallahu khairan.
Wassalam

Answer
Wa alaikum assalaam wa rahmatullahi wa barakaatuh,
May Allah reward you greatly for your dua' and Ameen.   May Allah give us purity of our intentions always. 
1.  Yes, we are allowed to lengthen the medd 'aaridh lissukoon 2, 4, or 6 vowel counts independent of the length we are using for al-medd al jaai'z and al-medd al-waajib. 

2.  In tareeq At-Tayyibah outlined by Imam ibn Al-Jazaree in his famous work An-Nashr, he found the authentic ways for qasr al-munfasil and wasit al-mutassil to have a sakt in the four known places for Hafs.This is what is outlined here on the site: http://www.abouttajweed.com/The%20Reading%20of%20Hafs%20with%20qasr%20munfasil%20wassit%20muttasil.pdf
What you most likely heard was the Sheikh reading by tareeq Rawdhah Al-Mu'addil which Imam Ibn Al-Jazaree did not include for Hafs 'an 'Aasim for qasr al-munfasil.  Please see:http://www.abouttajweed.com/kb/entry/119/

3.  There are many books which describe the rules for Hafs 'an Aasim by the way of Ash-Shaatibiyyah, and the tajweed rules themselves are the same for this and qasr munfasil except the words we have outlined here on the site.   You can find books by searching tajweed Hafs 'an 'Aasim in a search engine. 
One book we recommend is Tajweed Rules of the Qur'an by Ustadhah Kareema Czerepinski.  She is on the staff here.  For more information, please see: www.tajweedbooks.com

There is nothing you did wrong in asking the questions, may Allah make learning this science easy for you.  Asking questions is a way to learn more and for others to learn through your questions.   In general we prefer that questions are asked individually instead of multiple questions, but because your questions did not require long answers for each part, it was fine.  Baarak Allahu feekum. 
Wa asslaaam