The clause after -을락 말락 is mostly just the verb 하다, however in some situations you can see another clause or the verb being simply omitted.
Though not approved as standard, some may write the grammar point unspaced as -을락말락 and even put 하다 directly after it without space as well.
Sometimes, some speakers may mistakenly pronounce or write this grammar point as -을랑 말랑 (with or without space) as seen in example 3.