Karaites do not follow Torah Sh'be'al Peh! They only follow Torah Sh'bi' khtav. All these strict rulings come from Torah Sh'be'al Peh, so, what you say makes no sense at all. If they follow the strict rulings of Written Torah none of this nonsense taught by Rabbi Moshe Yehuda Leib Landa would have no impact on them at all.