Chazal fixed into the siddur to learn the chapter Ayzehu Mekoman and the beraisa of Rabi Yishmael after Parshas haTomid so everyone can merit to learn each day – pesukim, mishna and gemara. (ShA)
Only regarding tefilla, do we say that even without your understanding, Hashem understands your intentions. But reciting mishna and beraisa without your understanding does not count as learning. (MB2)
When you recite Ayzehu Mekoman or Bameh Madlikin or Pitum Haketores you should do so with the tune of mishnayos. (MB2)
You are allowed to say Ayzehu Mekoman at a mourner’s house because anything that is said as the order of the day is not prohibited to a mourner. (MB1)