assalamo Aleekom mr Omar , a very important thing I would like to bring to your attention , that Imam had explicitly announced that when with other worshippers who are not believers we should follow them in prayers so as not to cause more division and Not to create what could be considered as a new Muslim party , and as long as one is worshipping Allah alone , the pryier will be accepted god willing ,
As for your other questions I'll try to translate soon as I get some free time
Best regards
Allah,s blessings may be with you at all times