mimbar

Q: In order to create more space in the Musjid for Musallees on the occasion of Jumuah, we ask all the Musallees to move forward one step. The problem is that those Musallees in the first saff who are in line with the Mimbar, when they step forward, they have insufficient space for sajdah and thus make make sajdah on the step of the mimbar.

1.Is the Salaah of these Musallees valid?

2.If the Salaah is valid, is it Makrooh for them to make Sajdah in this manner?

3.In these circumstances, is it permissible to leave a gap in the first saff in line with the mimbar?

Q: Because of the Musjid being overcrowded and the mimbar being an obstruction in the first saff of the Musjid, a muqtadi happened to stand in the first saff directly in front of the mimbar, and when he (muqtadi) went into sajdah, his head touched the first step of the mimbar (he basically made the sajdahs with his head touching the first step of the mimbar). In the above mentioned case, was his (muqtadi's) salaah valid since he carried out his sajdahs in this manner?

Q: Is there any condition for the Imaam to firstly sit on the mimbar before standing up to deliver the Eid Khutbah, or can he just climb on the mimbar  deliver the khutba without first sitting down?

Q: Is it sunnah for the Imam to start ascending the mimbar with the right foot in order to give the Jumuah Khutba?