Salaah

Q: I recently found out when reading Salaah one should not skip one Surah between, e.g. during Magrib you should not read Surah Nasr and then Surah Ikhlaas. I know people skip two surahs, I’ve heard them read Surah Nasr and then Surah Falaq. So my question is, is it okay to skip if two or more surahs are skipped? 

My second question is if you are reading a long surah for example Surah Yaseen, is it okay to read the first 10 ayats in the first rakaat and then read from the 25th ayat to the 30ayat for the second rakaat? So basically skipping ayats and continuing? Is that allowed or is it Makrooh?

Q: Is it necessary to recite the Quraan Majeed with tajweed in Taraaweeh? Sometimes, due to reciting very fast, the tajweed is omitted.

Q: 

1. Is namaaz valid where there are many saffs empty in front of the musalli but he is in the musjid? 

2. What is the ruling regarding women coming in line or being in front of a male in the Haramain?

Q: 

1. What age is it suitable to start introducing a boy to the masjid, by taking him now and again? 

2. What age is it suitable to regularly bring a boy to the masjid for every salah?