A definitive answer concerning question 2:
The Hadith is in fact Saheeh, and was found in Sahih Bukhari, book 56 (Jihad), Hadith 18 of 294. Please view it here:
حَدَّثَنَا حَفْصُ بْنُ عُمَرَ الْحَوْضِيُّ، حَدَّثَنَا هَمَّامٌ، عَنْ إِسْحَاقَ، عَنْ أَنَسٍ ـ رضى الله عنه ـ قَالَ بَعَثَ...