Al-jawab billahi at-taufeeq (the answer with Allah's guidance)
1) Ahl-e Hadith, "the people of prophetic narrations" are not bound by Taqleed but consider themselves free to seek guidance in matters of religious faith and from the Quran and authentic traditions (Hadith). They refuse to acknowlege Ijma' (consensus) and Qiyas (analogical deductions) as a source of proof.
They are found predominately in the Middle East and South Asia, in particular, Pakistan and India.
Ahle Hadith as mentioned above reject the concept of Taqleed i.e. no particular school of thought should be followed. Those who have abandoned Taqleed are known as Ghair Muqallid.
2) Yes, it will be permissible. However, if they fear any types of mishaps and disputes etc. then it should be avoided, as marriage is something that requires compatibilty and understanding.