Re: 3 Surahs in 1 Rakaah
I have confirmed that from a hanafi scholar. We may recite many surahs in one rakah (keeping the sequence the same) as Hazrat Usman (r.a) and other Sahaba used to do so. It is preferable to recite Bismillah in the beginning of each of them, but it is not a compulsion. Also it is allowed to recite one ayah instead of a surah, thus reciting Ayat-al-Kursi is also allowed to be recited instead of a Surah.
Allah (swt) knows best!