1:
~ㄹ = [conjunctive, subjunctive]
만하다 = to be worth it;
both combined:
imaginable; reasonable; understandable
그 정도 가격이면 살 만하다: It would be quite a reasonable buy at such a price.
이 정도 손실을 입었으면 폐업도 할 만하다: Having suffered this much loss, even closing the whole business isn't out of question.
그런 말을 들었으니 어머니가 화 날 만하다: Having heard that, mom has every right to be angry.
2:
You won't see ~들다 very often since it's bound to only a few specific verbs.
It has the nuance of "to shrink", "to dive into"
You better memorize the few combined verbs as separate ones.
모닥불은 금새 사그러들었다: The campfire diminished soon enough.
폭풍은 점차 잦아들었다: The storm died away slowly
손수건은 피에 젖어들었다: The handkerchief was soaking up the blood
들판은 녹색으로 물들었다: The field got dyed green.
3:
말다 = to call off; to stop; to end
This one is tricky.
A) Something happened, and it's quite a mess
어제 숙제하다가 잠들고 말았다: I fell asleep yesterday while doing the homework. (And I'm in deep trouble now)
B) Not to care what happens next (out of displeasure)
감봉을 받아들이느니 그만두고 만다: I'd rather quit the job than accepting a salary cut. (showing off the middle finger)
Please note that "to fall asleep" is unintentional, thus regrettable while "to quit a job" is intentional, thus angry.
4:
Similar to 2), there are even less verbs ending with 빠지다 (excessively)
말라빠지다: to grow gaunt
약아빠지다: to be cunning
There might be more, but these are all I can tell you right now
Overall, ~빠지다 carries a very negative nuance due to an excess of something already negative.
~터지다 is similar to ~빠지다, covering an even wider range
느려터지다: excessively slow