هل يلزم قضاء الصلوات الفائتة بعد التوبة لمن كان تاركًا للصلاة ثم أصبح حنبليًّا، مع العلم أنه أخذ بقول من لا يرى وجوب القضاء قبل التَّحَنْبُل، وما دليل المالكية في عدم تفريط مَن يصلي يومين؟

There is no harm in being a Hanbali, and you are not required to adhere to the Hanbali madhhab in every matter. Rather, it is permissible for you to follow other madhahib in individual issues, relying on scholars whom you trust, as long as you do not intend to seek out dispensations. There is no harm upon you in adopting the Maliki opinion in the aforementioned issue, for seeking dispensations due to necessity is something many scholars permit, and this is not considered blameworthy conflation.