Shabbat, Tefillah and more

Question

Dear AA, 1) Follow up on a previous question: you said to follow the minhag of saying v'shamru on Friday night - what if I have not been saying it for years because of the chumra of my rosh yeshiva? 2) Why isn't singing eshet chayil a problem of singing pesukim? 3) Is it true that sefaradim are not supposed to put their heads on their arms during tachanun, or is this a mistaken minhag? 4) Are all forms of k'tav OK for sephardim, or should they use a specific one - ktav ari, sephardi or bet yosef? How about b'diavad? 5) Sometimes your father holds like the Beit Yosef with regard to halacha and sometimes not. Don't the sefardi acharonim all say that we follow the horaot of Maran whether they are lenient or stringent? (Maybe this is an old wives tale, like many so-called 'minhagim') Thank you as always.